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A simple cellulose acetate membrane-based small lanes technique for protein electrophoresis.
Na, Na; Liu, Tingting; Yang, Xiaojun; Sun, Binjie; Ouyang, Jenny; Ouyang, Jin
Combining electrophoresis with a cellulose acetate membrane-based technique, we developed a simple and low-cost method, named cellulose acetate membrane-based small lanes (CASL), for protein electrophoresis. A home-made capillary plotter controlled by a 3D moving stage was used to create milli-to-micro channels by printing poly(dimethylsiloxane) on to a hydrophilic cellulose acetate membrane. In the hydrophilic channels, 5 nL protein mixture was separated on the basis of electro-migration under an electric field. Compared with polyacrylamide gel electrophoresis (PAGE), CASL resulted in higher protein signal intensity for separation of mixtures containing the same mass of protein. The platform was easily fabricated at low cost (approx. $0.005 for each 1-mm-wide channel), and separation of three protein mixtures was completed in 15 min. Both electrophoresis time and potential affected the separation. Rather than chromatographic separation, this method accomplished application of microchannel techniques for cellulose acetate membrane-based protein electrophoresis. It has potential in proteomic analysis, especially for rapid, low-cost, and low-volume sample analysis in clinical diagnosis. PMID:22752445
Quantitative determination of sulfated glycopeptide by two-dimensional electrophoresis on cellulose acetate membrane.
Muramoto, K; Tanaka, H; Kimura, S; Kubo, K; Yoshihara, S; Yokoyama, M; Yoshida, Y; Endo, M
Quantitative determination of the sulfated glycoproteins present in tissue and secretion fluid was performed. After digestion of the specimen with pronase in order to convert glycoproteins to glycopeptides, the sulfated glycopeptides were separated from a mixture of acidic glycans (glycosaminoglycans, sialoglycopeptides and sulfated glycopeptides) by two-dimensional electrophoresis on cellulose acetate membrane [(1986) J. Biochem. Biophys. Methods 12, 239-246]. After staining with alcian blue, the spot of sulfated glycopeptide on the cellulose acetate membrane was cut out, and then only the dye bound to the sulfated glycopeptide was extracted with a 5% cetylpyridinium chloride solution at 100 degrees C for 15 min. The extract was then measured by absorbance at 615 nm using an authentic sulfated glycopeptide as a standard. This method facilitated the determination of sulfated glycopeptides, which were separated from other acidic glycans, within the range 0-25 micrograms. PMID:2809069
The quantification of oxygen toxicity by the technique of cellulose acetate electrophoresis of rat serum proteins
Barker, Marcia Wagner
by cardiac puncture before and after exposure periods and serum was aspirated from the clotted and centrifuged samples. Serum samples were subjected to electrophoresis on cellulose acetate and examined for qualitative and quantitative changes... be of importance in oxygen toxicity studies and in the treatment of newborns with hyaline membrane disease. Although the process of hyalinization is not well understood, work done by Phillips, Wyte, Weeks and Soloway (116) and by Fujikura (63) indicated a...
Supported molecular matrix electrophoresis: a new membrane electrophoresis for characterizing glycoproteins.
Matsuno, Yu-ki; Kameyama, Akihiko
Protein blotting is often used for identification and characterization of proteins on a membrane to which proteins separated by gel electrophoresis are transferred. The transferring process is sometimes problematic, in particular, for mucins and proteoglycans. Here, we describe a novel membrane electrophoresis technique, termed supported molecular matrix electrophoresis (SMME), in which a porous polyvinylidene difluoride (PVDF) membrane filter is used as the separation support. Proteins separated by this method can be immunoblotted without any transferring procedures. PMID:25117247
Fabricating PFPE Membranes for Capillary Electrophoresis
NASA Technical Reports Server (NTRS)
Lee, Michael C.; Willis, Peter A.; Greer, Frank; Rolland, Jason
A process has been developed for fabricating perfluoropolyether (PFPE) membranes that contain microscopic holes of precise sizes at precise locations. The membranes are to be incorporated into laboratory-on-a-chip microfluidic devices to be used in performing capillary electrophoresis. The present process is a modified version of part of the process, described in the immediately preceding article, that includes a step in which a liquid PFPE layer is cured into solid (membrane) form by use of ultraviolet light. In the present process, one exploits the fact that by masking some locations to prevent exposure to ultraviolet light, one can prevent curing of the PFPE in those locations. The uncured PFPE can be washed away from those locations in the subsequent release and cleaning steps. Thus, holes are formed in the membrane in those locations. The most straightforward way to implement the modification is to use, during the ultraviolet-curing step, an ultraviolet photomask similar to the photomasks used in fabricating microelectronic devices. In lieu of such a photomask, one could use a mask made of any patternable ultraviolet-absorbing material (for example, an ink or a photoresist).
Diffusion of benzocaine in poly(ethylene-vinyl acetate) membranes: Effects of vehicle ethanol concentration and membrane vinyl acetate content
Shirlynn X. Chen; Richard T. Lostritto
The effect of vehicle ethanol concentration and membrane vinyl acetate (VA) content on the diffusion properties of poly (ethylene-vinyl acetate) (EVA) membranes was studied. The maximum flux of a model drug, benzocaine, through EVA membranes increases with increasing ethanol concentration and membrane VA content. The flux enhancement is attributed to the increases of both benzocaine membrane solubility and diffusivity. For
[Electrophoresis on a cellulose acetate CAE in a study of commercial active alginate dressings].
Pielesz, Anna
Hydrogels are cross-linked three-dimensional macromolecular networks that contain a large fraction of water within their structure. One of the most important properties of alginate hydrogels, leading to their broad versatility, is their ability for controlled uptake, release and retention of molecules. This ability, in turn, is due to specific interactions of the macromolecular network with the diffusing or retained molecule, for example ions. In this study, water-soluble sodium alginates contained in active dressings Medisorb A were identified using electrophoresis on cellulose acetate CAE. The presence of guluronic acid (G) and mannuronic acid (M) residues in hydrolysates of alginic acid AA (used as reference substance) and active alginate dressings Medisorb A was also proved. "Egg-box" structures, earlier described in literature, were observed using the same technique and their interpretation was attempted. Electrophoresis on cellulose acetate was found to be a useful method for examining alginate-based biomaterials. PMID:20099737
Original article Two-dimensional gel electrophoresis of membrane
Paris-Sud XI, Université de
Original article Two-dimensional gel electrophoresis of membrane proteins from ectomycorrhizal-dimensional polyacrylamide gels. Gels with limited back- ground staining and streaking and with clearly efficacité et leur compatibilité avec l'obtention de gels d'électro- phorèse bidimensionnelle. Une fraction
Conformational dynamics of DNA-electrophoresis on cationic membranes.
Kahl, Valentin; Hennig, Martin; Maier, Berenike; R�dler, Joachim O
The conformational dynamics of DNA molecules undergoing electrophoresis on a fluid substrate-supported cationic lipid bilayer is investigated using fluorescence microscopy. At low electrophoretic velocities, drift of 2-D random coils is observed. In contrast, at velocities larger than 0.3 mum/s, the DNA molecules stretch out and assume branched configurations. The cross-over scenario is explained by the observation that cationic lipids segregate underneath the adsorbed DNA and confine the DNA to its counter charge imprint on time scales shorter than the relaxation time of the imprint. The concept of a tube-like confinement of the DNA is corroborated by the observed 1/N size dependence of the electrophoretic mobility in analogy to the biased reptation model in gels. The role of membrane defects and possible applications of membrane-based electrophoresis in microfluidic devices are discussed. PMID:19294687
Isolation of Spiroplasma citri membranes and characterization of membrane proteins by two-dimensional gel electrophoresis
Philippe Simoneau; Jacques Labar�re
This paper describes a method for isolating plasma membranes fromSpiroplasma citri and for comparing membrane and cytoplasmic proteins by two-dimensional gel electrophoresis. Plasma membranes ofS. citri were stabilized against fragmentation by coating cell with Concanavalin A just prior to lysis. After lysis of the cells by ultrasonic irradiation, membranes were purified by differential centrifugation and step gradients. The purified fraction,
Fucoidan as an inhibitor of thermally induced collagen glycation examined by acetate electrophoresis.
Pielesz, Anna; Paluch, Jadwiga
Non-enzymatic glycation (Maillard reaction) in vitro could be a simple method to obtain glycoconjugates for studying their biological properties. Hence, fucoidan was retained by acetate electrophoresis indicating a strong interaction with the protein. A loss of colour in fucoidan bands was found for samples incubated with collagen as compared with samples of free fucoidan. Also under in vitro conditions at 100�C - simulating a sudden burn incident - fucoidan binds with collagen as a result of the Maillard reaction. In contrast, the colour of the fucoidan bands intensified for samples incubated with collagen, with the addition of glucose. Electrophoretic analyses were carried out after heating the samples to a temperature simulating a burn incident. The bands were found to intensify for samples incubated with collagen during a 30-day-long incubation. Thus, spontaneous in vitro glycation - i.e. without the addition of glucose - was confirmed. This process is highly intensified both by the temperature and time of incubation. For a sample incubated in vitro in a fucoidan solution containing glucose, glycation was confirmed in a preliminary FTIR and acetate electrophoresis examinations, occurring in collagen obtained from chicken skins. In particular, a new band emerging around 1746 cm(-1) was observed for above samples, as was its increasing intensity, as compared with samples without the addition of glucose. In the collagen glycation assay, while glucose reacts with collagen and forms cross-linked aggregates, fucoidan decreases the process of aggregation and recovery of native collagen. PMID:24853731
Continuous-flow electrophoresis: Membrane-associated deviations of buffer pH and conductivity
NASA Technical Reports Server (NTRS)
Smolka, A. J. K.; Mcguire, J. K.
The deviations in buffer pH and conductivity which occur near the electrode membranes in continuous-flow electrophoresis were studied in the Beckman charged particle electrophoresis system and the Hanning FF-5 preparative electrophoresis instrument. The nature of the membranes separating the electrode compartments from the electrophoresis chamber, the electric field strength, and the flow rate of electrophoresis buffer were all found to influence the formation of the pH and conductivity gradients. Variations in electrode buffer flow rate and the time of electrophoresis were less important. The results obtained supported the hypothesis that a combination of Donnan membrane effects and the differing ionic mobilities in the electrophoresis buffer was responsible for the formation of the gradients. The significance of the results for the design and stable operation of continuous-flow electrophoresis apparatus was discussed.
Comparative analysis of cellulose acetate hemoglobin electrophoresis and high performance liquid chromatography for quantitative determination of hemoglobin A2
Khosa, Shafi Mohammad; Moinuddin, Moinuddin; Mehmood, Hassan Osman; Qamar, Khansa
Background The present study is designed to evaluate the reliability and cost effectiveness of cellulose acetate Hb electrophoresis and high performance liquid chromatography (HPLC) in the determination of HbA2 levels. Methods The test population comprised 160 individuals divided into four groups: normal individuals, ?-thalassemia trait (BTT) patients, iron deficiency anemia (IDA) patients, and co-morbid patients (BTT with IDA). HbA2 levels determined using cellulose acetate Hb electrophoresis and HPLC were compared. Results HbA2 levels were found to be diagnostic for classical BTT using either method. In co-morbid cases, both techniques failed to diagnose all cases of BTT. The sensitivity, specificity, and Youden's index for detection of the co-morbid condition was 69% and 66% for HPLC and cellulose acetate Hb electrophoresis, respectively. Conclusion This study revealed that semi-automated cellulose acetate Hb electrophoresis is more suitable for use in ?-thalassemia prevention programs in low-income countries like Pakistan. This technique is easily available, simple and cost effective.
Dissolution control of Mg by cellulose acetate-polyelectrolyte membranes.
Yliniemi, Kirsi; Wilson, Benjamin P; Singer, Ferdinand; H�hn, Sarah; Kontturi, Eero; Virtanen, Sannakaisa
Cellulose acetate (CA)-based membranes are used for Mg dissolution control: the permeability of the membrane is adjusted by additions of the polyelectrolyte, poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA). Spin-coated films were characterized with FT-IR, and once exposed to an aqueous solution the film distends and starts acting as a membrane which controls the flow of ions and H2 gas. Electrochemical measurements (linear sweep voltammograms, open-circuit potential, and polarization) show that by altering the CA:PDMAEMA ratio the dissolution rate of Mg can be controlled. Such a control over Mg dissolution is crucial if Mg is to be considered as a viable, temporary biomedical implant material. Furthermore, the accumulation of corrosion products between the membrane and the sample diminishes the undesirable effects of high local pH and H2 formation which takes place during the corrosion process. PMID:25426707
Ion selective permeation through cellulose acetate membranes in forward osmosis.
Irvine, Gavin J; Rajesh, Sahadevan; Georgiadis, Michael; Phillip, William A
Solute-solute interactions can have a dramatic impact on the permeation of solutes through dense polymeric membranes. In particular, understanding how solute-solute interactions can affect the design of osmotically driven membrane processes (ODMPs) is critical to the successful development of these emerging water treatment and energy generation processes. In this work, we investigate the influence that solute-solute interactions have on nitrate permeation through an asymmetric cellulose acetate forward osmosis membrane. A series of experiments that included systematic modifications to the cation paired with nitrate, the identity of the draw solute, and the solution pH were conducted. These experiments reveal that in the unique operating geometry of ODMPs, where solute containing solutions are present on both sides of the membrane, nitrate fluxes are significantly higher (>15 times in some cases) than predicted by existing models for solute permeation in ODMPs. The identity of the cation paired with nitrate influences the flux of nitrate; the identity of the cation in the draw solution does not affect the flux of nitrate; however, the identity of the anion in the draw solution has the most significant impact on the flux of nitrate. These results suggest that an ion exchange mechanism, which allows nitrate to switch rapidly with anions from the draw solution, is present when cellulose acetate based membranes are used in ODMPs. PMID:24152190
Application of cellulose acetate butyrate-based membrane for osmotic drug delivery
Anant Shanbhag; Brian Barclay; Joanna Koziara; Padmaja Shivanand
The release rate of drugs from an OROS is controlled by semipermeable membranes composed typically of cellulose acetate (CA) with various flux enhancers. Cellulose\\u000a acetate butyrate (CAB) was identified as a viable alternative. The CAB membrane matched the CA membrane in robustness but\\u000a had superior drying properties, offering particular advantages for thermolabile formulations. Studies were conducted to characterize\\u000a CAB membrane
Membrane interfaces for sample introduction in capillary zone electrophoresis
Bao, L.; Dasgupta, P.K. [Texas Tech Univ., Lubbock, TX (United States)
Small lengths of narrow-bore tubular membranes can be interposed in the separation capillary in capillary electrophoretic separation systems. These membrane segments can be used as sampling interfaces; a jacket is built outside the membrane, and the sample is introduced by diffusion/permeation through the membrane. Various examples are shown; the determination of gaseous samples through a porous membrane, the determination of ionizable/nonionic solutes by permeation through a silicone rubber membrane, and the separation of low MW constituents in blood plasma by transport through a dialysis membrane. In the first two cases, significant preconcentration is possible, thus permitting attractive detection limits. 23 refs., 10 figs., 2 tabs.
Role of membrane surface morphology in colloidal fouling of cellulose acetate and composite aromatic polyamide reverse osmosis membranes
Menachem Elimelech; Xiaohua Zhu; Amy E. Childress; Seungkwan Hong
Laboratory-scale colloidal fouling tests, comparing the fouling behavior of cellulose acetate and aromatic polyamide thin-film composite reverse osmosis (RO) membranes, are reported. Fouling of both membranes was studied at identical initial permeation rates so that the effect of the transverse hydrodynamic force (permeation drag) on the fouling of both membranes is comparable. Results showed a significantly higher fouling rate for
Acetate Kinase in the Genus Veillonella: Effect of Succinate, Serological Cross-Reactivity, and Separation by Electrophoresis
Yoshimura, Fuminobu; Kasai, Noriyuki; Sugawara, Bin; Suzuki, Takeshi
Acetate kinases from the genus Veillonella were divided into two types: a succinate-stimulated enzyme and a succinate-independent enzyme. Three strains, V. parvula ATCC 17743 (antigenic group II), V. parvula ATCC 17744 (V), and V. parvula ATCC 10790 (VI), contained the succinate-stimulated enzyme. Among four types strains of V. alcalescens, three strains, ATCC 17747 (I), ATCC 17746 (III), and ATCC 17748 (VII), contained the succinate-independent enzyme, whereas only one strain, ATCC 17745 (IV), contained the succinate-stimulated enzyme. Small amounts of antiserum to the purified acetate kinase from V. alcalescens ATCC 17748 completely inhibited the purified and crude enzyme activity from the strain. Classification of the enzymes on the basis of stimulation by succinate was consistent with classification based on serological reactions using the antiserum as an independent parameter. The succinate-stimulated enzyme could be separated into two classes according to the degree of sensitivity to succinate: (i) enzymes from V. parvula ATCC 17744 and V. alcalescens ATCC 17745, which could be demonstrated on gel after electrophoresis by a histochemical method to be highly stimulated by the presence of succinate in the reaction mixture, and (ii) enzymes from V. parvula ATCC 10790 and V. parvula ATCC 17743, which could be easily demonstrated without succinate. Four groups of acetate kinases from the genus Veillonella were separated by gel electrophoretic mobility. The results showed that almost all enzymes from the seven type strains were heterogeneous at the molecular level. Images PMID:6154045
Poly(vinyl chloride) polyacrylonitrile composite membranes for the dehydration of acetic acid
G. H. Koops; J. A. M. Nolten-Oude Hendrikman; M. H. V. Mulder; C. A. Smolders
Composite membranes have been prepared consisting of a poly(vinyl chloride) (PVC) top layer on either a dense polyacrylonitrile (PAN) layer (bi-layer membrane) or a porous PAN support layer (normal composite membrane) and studied with respect to the dehydration of acetic acid. Especially, the influence of the surface porosity of the porous support layer on the selectivity and flux was studied
Chelation and permeation of heavy metals using affinity membranes from cellulose acetate�chitosan blends
M. M. Naim; H. E. M. Abdel Razek
Affinity membranes have attracted the attention of membrane researchers especially in the field of wastewater treatment specifically in removing heavy metals by chelation from aqueous solutions. In the present work, several membranes are made from either cellulose di-acetate (CA) or CA together with chitosan (CS) solutions, the CS prepared in our lab from shrimp shells or from readymade shrimp or
Demystifying Hardy-Weinberg: Using Cellulose Acetate Electrophoresis of the Lap Locus to Study Population Genetics in White Campion (Silene latifolia)
NSDL National Science Digital Library
Patricia A. Peroni (Davidson College; )
This laboratory exercise could used as an introductory biology lab and/or an upper level course lab, with minor adjustments, covering ecology, evolution, population genetics and physiology. Population genetics is explored using seedlings from several population of the perennial herb white campion, (Silene latifolia), scientific method,cellulose acetate protein electrophoresis and the Hardy-Weinberg Equilibrium Theory.
Proteoliposome-based capillary electrophoresis for screening membrane protein inhibitors.
Li, Bing; Lv, Xuefei; Geng, Lina; Qing, Hong; Deng, Yulin
A method for screening of monoamine oxidase (MAO) inhibitor was carried out using capillary electrophoresis (CE) based on the interaction of MAO and its substrate kynuramine (Kyn). Bioactive proteoliposome was reconstituted by liposome and MAO and then was applied as the pseudostationary phase (PSP) of CE to mimic the interaction between the enzyme and its substrate. N-prolmrgyl-R-2-heptylamine (R-2-HPA) and rasagiline [N-propargyl-1-(R)-aminoindan], which are two kinds of MAO inhibitors, were added into the running buffers containing proteoliposome. The results showed that the relative migration time ratio (RMTR � 10(-1)) values of Kyn were enhanced from 8.88 to 9.31 with an increase of the concentrations of rasagiline from 10(-6) to 1 mM. However, the RMTR values of Kyn were enhanced from 8.83 to 9.14 with an increase of the concentrations of R-2-HPA from 10(-6) to 1 mM. The RMTR value of Kyn in the presence of rasagiline was larger than that in the presence of R-2-HPA when rasagiline and R-2-HPA were at the same concentration. The results indicated that the interaction between Kyn and MAO was weakened with the increase of the inhibitors. In addition, the results of offline incubation showed that the inhibitions of rasagiline were 100.0, 72.1, 51.8 and 5.4% at the concentration of 1, 10(-2), 10(-4) and 10(-6) mM; moreover, the inhibitions of R-2-HPA were 70.0, 44.9, 4.1 and 0.9% at the concentrations of 1, 10(-2), 10(-4) and 10(-6) mM. The inhibition efficiency of rasagiline was stronger than that of R-2-HPA at the same concentration. Additionally, the interaction between Kyn and liposome was also investigated. This newly developed method might provide a potential tool for screening MAO inhibitor. PMID:22547660
Continuous Ethanol Production with a Membrane Bioreactor at High Acetic Acid Concentrations
Ylitervo, P�ivi; Franz�n, Carl Johan; Taherzadeh, Mohammad J.
The release of inhibitory concentrations of acetic acid from lignocellulosic raw materials during hydrolysis is one of the main concerns for 2nd generation ethanol production. The undissociated form of acetic acid can enter the cell by diffusion through the plasma membrane and trigger several toxic effects, such as uncoupling and lowered intracellular pH. The effect of acetic acid on the ethanol production was investigated in continuous cultivations by adding medium containing 2.5 to 20.0 g�L?1 acetic acid at pH 5.0, at a dilution rate of 0.5 h?1. The cultivations were performed at both high (~25 g�L?1) and very high (100�200 g�L?1) yeast concentration by retaining the yeast cells inside the reactor by a cross-flow membrane in a membrane bioreactor. The yeast was able to steadily produce ethanol from 25 g�L?1 sucrose, at volumetric rates of 5�6 g�L?1�h?1 at acetic acid concentrations up to 15.0 g�L?1. However, the yeast continued to produce ethanol also at a concentration of 20 g�L?1 acetic acid but at a declining rate. The study thereby demonstrates the great potential of the membrane bioreactor for improving the robustness of the ethanol production based on lignocellulosic raw materials. PMID:25028956
Studies on bipolar membranes. Part II � Conversion of sodium acetate to acetic acid and sodium hydroxide
G. S. Trivedi; B. G. Shah; S. K. Adhikary; V. K. Indusekhar; R. Rangarajan
The electrodialytic water-splitting technology using bipolar membrane is an attractive cost-effective process for the production of acids and alkalies from the corresponding salts occurring in waste waters. Earlier report by us described the preparation of bipolar membranes and its application in converting sodium sulfate into sulfuric acid and sodium hydroxide. In this paper, as an extension of our earlier published
Whisker growth by means of cellulose acetate membranes: NaCl and KCl
NASA Astrophysics Data System (ADS)
Yellin, N.; Zelingher, N.; Ben-Dor, L.
NaCl and KCl whiskers were successfully grown from non-concentrated solutions by means of cellulose acetate (CA) membranes. Substantial growth was obtained within several hours on the part of the membrane not submerged in the solution. It is possible to do this with the mother liquor concentration barely affected by the whisker growth. The growth rate is controlled by water evaporation from the membrane. The driving force of the process in the case of NaCl and KCl solutions is the evaporation of water and the membrane affinity for it.
Membrane applications to coal conversion processes. Quarterly report, June 5September 4, 1975. [Cellulose acetate butyrate; polysulfone; 14 refs
W. J. Schell; W. M. King; R. W. Lawrence; R. E. Jr. Mann
A survey of coal conversion processes was conducted to determine the appropriate application of membrane gas separation methods. This study included a review of gas stream compositions, pressures, and temperatures, the incorporation of membrane treatment to these gas streams, and other commercial separation processes that may be comparable to membrane separation. Characterization of currently available cellulose acetate membranes constituted a
Effectiveness and limitation of two-dimensional gel electrophoresis in bacterial membrane protein proteomics and perspectives.
Bunai, Keigo; Yamane, Kunio
Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) using isoelectric focusing and SDS-PAGE in the first and second dimensions, respectively, is an established means of simultaneously separating over 1000 proteins and two new types have recently been developed. These procedures have significant shortcomings such as low load ability and poor separation of hydrophobic, acidic and alkaline proteins. We therefore modified the protocols to analyze the Bacillus subtilis membrane proteome. The 2D-PAGE techniques effectively separated membrane proteins having one and two transmembrane segments but not those with more than four. Compared with new LC/MS/MS procedures that are independent of electrophoretic separation, 2D-PAGE can globally analyze and quantify proteins at various stages of the cell cycle when labeled with isotopes such as 35S-methionine or the stable isotope, 15N. PMID:15652812
Non-denaturing gel electrophoresis system for the purification of membrane bound proteins
Cavinato, A.G.; Macleod, R.M.; Ahmed, M.S.
A new method is described for the purification of a membrane bound glycoprotein, the kappa opioid receptor from human placental tissue. The method uses preparative slab-gel electrophoresis in the presence of the non-denaturing detergent CHAPS. A linear relationship between log molecular weight and SDS PAGE electrophoretic mobility of known molecular weight markers, in the presence of CHAPS, is observed. Using this method, we were able partially to purify an /sup 3/H-etorphine binding glycoprotein, from placental villus tissue, with an apparent molecular weight range of 60-70,000. The iodinated glycoprotein migrates in SDS PAGE with an apparent molecular weight of 63,000. This method may be useful for the isolation of membrane bound proteins, especially when an affinity ligand is not available.
Study of ABO blood types by combining membrane electrophoresis with surface-enhanced Raman spectroscopy
NASA Astrophysics Data System (ADS)
Wang, Jing; Lin, Juqiang; Huang, Zufang; Sun, Liqing; Shao, Yonghong; Lu, Peng; Shi, Wei; Lin, Jinyong; Chen, Rong
The molecular characterization of ABO blood types, which is clinically significant in blood transfusion, has clinical and anthropological importance. Polymerase chain reaction sequence-based typing (PCR-SBT) is one of the most commonly used methods for the analysis of genetic bases of ABO blood types. However, such methods as PCR-SBT are time-consuming and are high in demand of equipments and manipulative skill. Here we showed that membrane electrophoresis based SERS method employed for studying the molecular bases of ABO blood types can provide rapidand easy-operation with high sensitivity and specificity. The plasma proteins were firstly purified by membrane electrophoresis and then mixed with silver nanoparticles to perform SERS detection. We use this method to classify different blood types, including blood type A (n=13), blood type B (n=9) and blood type O (n=10). Combination of principal component analysis (PCA) and liner discriminant analysis (LDA) was then performed on the SERS spectra of purified albumin, showing good classification results among different blood types. Our experimental outcomes represent a critical step towards the rapid, convenient and accurate identification of ABO blood types.
Nuclear magnetic resonance study of acetic acid permeation of large unilamellar vesicle membranes.
Alger, J R; Prestegard, J H
The permeation of acetic acid through large unilamellar phospholipid vesicle membranes has been investigated using the unique capability of nuclear magnetic resonance to characterize flow under pseudo-equilibrium conditions. Two types of experiments have been employed: total line shape analysis and selective population transfer. These techniques are sensitive to permeation on time scales ranging form 0.001 to 10.0 s. The permeation rate dependence on pH and acetic acid concentration indicates that the neutral acetic acid monomer is the dominant permeant species with a permeation coefficient of 5 +/- 2 x 10-4 cm/s. Mechanisms of permeation and the applicability of nuclear magnetic resonance methodology are discussed. PMID:262441
The wettability of a cellulose acetate membrane in the presence of bovine serum albumin
NASA Astrophysics Data System (ADS)
Bia?opiotrowicz, Tomasz; Ja?czuk, Bronis?aw
The measurements of the contact angle for water (W), glycerol (G), formamide (F), ethylene glycol (E) and diiodomethane (D) on a bare cellulose acetate membrane and covered by adsorptive bovine serum albumin (BSA) films were made. The adsorption was performed from solutions in concentration range 0-100 mg/ml. An influence of the membrane porosity on an apparent contact angle was discussed and Cassie and Baxter equation was used for that purpose. It was suggested that some liquids could penetrate in to membrane pores reducing its apparent porosity. To explain such behaviour, the spreading coefficient and the work of adhesion was calculated for the studied liquids. Components and parameters of the surface free energy of a bare cellulose acetate membrane and covered by an adsorptive BSA film were determined for W-G-D, W-F-D and G-F-D three-liquid systems and they were similar for these systems. However, for the hydrated BSA layer those components and parameters for the systems W-G-D, W-F-D were different than those for the system G-F-D. It was stated that after BSA adsorption on that membrane percentage of empty pores decreased, reducing their number almost to 0, at the highest BSA concentrations.
Immobilized phospholipid capillary electrophoresis for study of drug-membrane interactions and prediction of drug activity.
Mei, Jie; Xu, Jian-Rong; Xiao, Yu-Xiu; Zhang, Qian-Rui; Feng, Yu-Qi
Immobilized phospholipid capillary electrophoresis (IPCE) was developed for studying the interactions between a set of nonsteroidal anti-inflammatory drugs (NSAIDs) and membrane and predicting the biological activity of NSAIDs. Supported vesicle layers and supported phospholipid bilayers were attached to the inner surface of a capillary wall simply by rinsing with liposome solutions. The liposomes, composed of soybean phosphatidylcholine (SPC) or SPC and different proportions of cholesterol (Ch), were small unilamellar vesicles prepared by sonication. The normalized capacity factor (K(IPCE)) was introduced into IPCE for evaluating drug-membrane interactions. Related theories and equations were derived to calculate K(IPCE) values from apparent migration time of a solute and electroosmotic flow. The strong relationships were observed between logK(IPCE) (SPC) values and logK(lw) values (the partition coefficients determined in free SPC-liposome partitioning system) (R=0.9855 and P<0.0001) or logK(ILC) values (the normalized capacity factors determined by immobilized POPC-liposome chromatography, POPC represents 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) (R=0.9875 and P<0.0001). In addition, logK(IPCE) (SPC/Ch 80:20%) values correlated well with the pIC50 (the minus logarithm of IC50) values for cyclooxygenase 2 determined on intact cells (R=0.959 and P<0.001). These results confirmed that IPCE, K(IPCE) value as evaluation index, can be effectually used for studying drug-membrane interactions and it has the potential to predict drug activity. Cholesterol-containing (20 mol%) liposomes may be more suitable to mimic real cell membrane. PMID:18371854
Surface and charge transport characterization of polyaniline-cellulose acetate composite membranes.
Qaiser, Asif A; Hyland, Margaret M; Patterson, Darrell A
This study elucidates the charge transport processes of polyaniline (PANI) composite membranes and correlates them to the PANI deposition site and the extent of PANI surface layering on the base microporous membranes. PANI was deposited either as a surface layer or inside the pores of cellulose acetate microporous membranes using various in situ chemical polymerization techniques. The extent of PANI layering at the surface of the base membrane and its oxidation and doping states were characterized using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). PANI deposition on the membranes showed a strong dependence on the polymerization technique and polymerization time within a single technique. In XPS, the deconvolution of C 1s and N 1s core-level spectra of the composite membranes was used to quantify the extent of PANI layering at the surface along with its oxidation and doping states. PANI incompletely covered the surface of the base microporous membranes for all the employed techniques. However, the extent of the layering increased with the polymerization time in a particular technique. The charge transport through the bulk membrane and charge transfer at the membrane/electrode interface were studied by electrochemical impedance spectroscopy (EIS). The data were analyzed using the equivalent circuit modeling technique. The modeling parameters revealed that PANI deposition at the surface enhanced the interfacial charge transfer but the process depended on the extent of the surface coverage of the membrane. In addition, the charge transport in the bulk membrane depended on the PANI intercalation level, which varied depending on the polymerization technique employed. In addition, the EIS of electrolyte-soaked membranes was also conducted to evaluate the effects of PANI deposition site on charge transport in the presence of an electrolyte. PANI layering at the pore walls of the base membrane from diaphragmatic polymerization in a two-compartment cell showed that charge transport processes were strongly affected by the interaction of the electrolyte with the PANI layer at the pore surface. This study successfully showed the dependence of charge transport mechanisms of PANI composite membranes on the PANI deposition site and extent of surface layering at the membrane surface. PMID:21287993
Post radiation grafting of vinyl acetate onto low density polyethylene films: Preparation and properties of membrane
NASA Astrophysics Data System (ADS)
M. Dessouki, Ahmed
Reverse osmosis membranes were prepared by the post radiation grafting of vinyl acetate onto low density polyethylene films. The factors affecting the grafting process such as radiation dose, monomer concentration and temperature on the grafting yield were studied. It was found that the dependence of the grafting rate on radiation intensity and monomer concentration was found to be of 0.64 and 1.4 order, respectively. The activation energy for this grafting system was calculated and found to be 4.45 kcal/mol above 30�C. Some properties of the grafted films such as specific electric resistance, water uptake, mechanical properties and thermal and chemical stability were investigated. An improvement in these properties was observed which makes possible the use of these membranes in some practical applications. The use of such membranes for reverse osmosis desalination of saline water was tested. The effect of operating time, degree of grafting and applied pressure on the water flux and salt rejection were determined. The results showed salt rejection percent over 90% and a reasonable water flux. A suitable degree of grafting of the membrane was determined as well as the optimum applied pressure.
ProteinAnalysis Electrophoresis
Lebendiker, Mario
, & Sterols PAGE IEF (Acrylamide) Agarose Gel PVDF Membrane Cellulose Acetate Membrane Nitrocellulose Membrane Nylon Membrane MALDI-MS High Sensitivity (10 ng) Higher Sensitivity (1 ng) Highest Sensitivity (0.1 ng
A novel blood plasma analysis technique combining membrane electrophoresis with silver nanoparticle-based SERS spectroscopy for potential applications in noninvasive cancer detection
Juqiang Lin; Rong Chen; Shangyuan Feng; Jianji Pan; Yongzeng Li; Guannan Chen; Min Cheng; Zufang Huang; Yun Yu; Haishan Zeng
Combining membrane electrophoresis with silver nanoparticle-based surface-enhanced Raman spectroscopy (SERS), we have developed a novel method for blood plasma analysis for cancer detection applications. In this method, total serum proteins are isolated from blood plasma by membrane electrophoresis and mixed with silver nanoparticles to perform SERS spectral analysis. The obtained SERS spectra present information-rich, fingerprint-type signatures of the biochemical constituents
A novel, post-column micro-membrane reactor for fluorescent analysis of protein in capillary electrophoresis.
Liu, Fan; Zhang, Lingyi; Qian, Junhong; Ren, Jun; Gao, Fangyuan; Zhang, Weibing
Based on the semipermeability of hollow fiber membranes, a post-column membrane reactor was developed for capillary electrophoresis (CE)-laser induced fluorescence (LIF) analysis of proteins by using a hollow fiber membrane to connect the separation and detection capillaries. The membrane length between the separation and detection capillaries was 1 mm. Driven by the chemical potential difference between the separation buffer inside the membrane and the fluorescence derivatization solution outside the membrane, the derivatization reagent can be easily drawn into hollow fiber membrane to react with proteins. Also, the separation buffer can be adjusted by the derivatization solution to match the conditions of derivatization without sample loss. The effect of the separation buffer on the derivatization reaction was investigated and the results showed that even a strong acidic solution and multiple additives can be adopted in the separation buffer without destroying the post-column derivatization of proteins. Under the optimized conditions, the highly sensitive detection of BSA was achieved with a detection limit of 3.3 nmol�L(-1) and a linear calibration range from 0.007 to 0.1 mg�mL(-1). The proposed CE-LIF system with a post-column membrane reactor was also successfully applied to the separation and detection of proteins in rat liver and loach muscle. PMID:24015400
Membrane-supported liquid-liquid-liquid microextraction combined with anion-selective exhaustive injection capillary electrophoresis-ultraviolet detection for sensitive analysis of phytohormones.
Huang, Linfang; He, Man; Chen, Beibei; Hu, Bin
A novel method based on off-line membrane-supported liquid-liquid-liquid microextraction (MS-LLLME) combined with on-column anion-selective exhaustive injection (ASEI) capillary electrophoresis-ultraviolet (CE-UV) detection was established for the analysis of seven phytohormones (abscisic acid (ABA), jasmonic acid (JA), 2,4-dichlorophenoxyacetic acid (2,4-D), 1-naphthalene acetic acid (NAA), indole-3-acetic acid (IAA), salicylic acid (SA) and gibberellic acid (GA)). In MS-LLLME, the target phytohormones were extracted from the acid donor phase to the alkaline acceptor phase, and the acceptor solutions were directly analyzed by ASEI-CE-UV. Under the optimal experimental conditions, the analytical performance of the method was evaluated. The limits of detection (LODs) of ABA, JA, 2,4-D, NAA, IAA, SA and GA were determined to be 1.00, 2.21, 0.33, 0.17, 0.67, 0.05 and 16.5ng/mL, respectively. The relative standard deviations (RSDs, n=7) ranged from 4.7% to 12.9%, and the enrichment factors were in the range of 307 to 20,160. The proposed method was successfully applied for the determination of multiple phytohormones in banana, cabbage and cucumber extracts, and ABA, IAA and SA were detected in these samples. The recoveries for the spiked samples were in the range of 79.0 to 116.4%. The proposed method was demonstrated to be suitable for the simultaneous quantification of multiple phytohormones with high sensitivity and good sample cleanup ability. PMID:24720904
Sensitivity enhancement in direct coupling of supported liquid membrane extractions to capillary electrophoresis by means of transient isotachophoresis and large electrokinetic injections.
Pant??kov�, Pavla; Kub�?, Pavel; Bo?ek, Petr
Enhanced sensitivity for determination of basic drugs in body fluids was achieved by in-line coupling of extraction across supported liquid membrane (SLM) to large electrokinetic injection and transient isotachophoresis-capillary zone electrophoresis (tITP-CZE) in commercial CZE instrument. Twelve cm long tITP plug of 300mM ammonium acetate was formed in the separation capillary just before the electrokinetic injection of acceptor solution containing nortriptyline, haloperidol and loperamide extracted across the SLM. The tITP plug ensured efficient stacking and preconcentration of the injected basic drugs due to the tITP action of ammonium and the drugs were then separated by CZE using 5.2M acetic acid as background electrolyte. No interferences were observed from highly-abundant body fluid species (NaCl and human serum albumin) due to the excellent clean-up properties of SLMs and analytical sensitivity increased up to 340 times compared to SLM extractions coupled in-line to CZE with standard hydrodynamic injections. The SLM-tITP-CZE method was characterized by good repeatability (RSDs of peak areas below 7.8%), linearity over two orders of magnitude (r(2) better than 0.994) and limits of detection (defined as 3�S/N) between 3 and 45?g/L. Interfacing of SLM extractions to CZE instrumentation was achieved by low-cost, disposable micro-extraction devices, which can be routinely prepared in every analytical laboratory. These devices eliminated sample carry-over, minimized the need for manual sample handling and ensured fully automated determination (including extraction, injection, preconcentration and separation) of the three basic drugs in 20?L of untreated body fluids. PMID:25747667
Development and optimization of a capillary zone electrophoresis technique for simultaneous determination of miconazole nitrate and hydrocortisone acetate in a cream pharmaceutical formulation.
Korany, Mohamed A; Maher, Hadir M; Galal, Shereen M; Ragab, Marwa A A
A simple, fast, inexpensive, and reliable capillary zone electrophoresis (CZE) method for the determination of a mixture of miconazole nitrate (MCZ) and hydrocortisone acetate (HCZ) in a cream formulation has been developed and validated. Optimum conditions were sodium dihydrogen phosphate buffer (50 mM, pH 4) and 30 kV applied voltage in a 85 cm x 75 pm id capillary. Direct UV detection at 230 nm led to adequate sensitivity without interference from the sample excipients. MCZ and HCZ migrated in approximately 165 and 415 s, respectively. The analytical curves had a coefficient of correlation, r, of 0.9999 and 0.9996 for MCZ and HCZ, respectively. The LOD and LOQ were 0.28 and 0.93 microg/mL for MCZ and 0.38 and 1.27 microg/mL for HCZ, respectively. Thus, excellent accuracy and precision were obtained. Recoveries varied from 98 to 102%, and intraday and interday precision, calculated as the RSD, were less than 2.0% for each drug. The proposed CZE method displayed advantageous performance characteristics and can be considered suitable for QC of the MCZ and HCZ cream formulation. PMID:24645507
Fouling propensity and separation efficiency of epoxidated polyethersulfone incorporated cellulose acetate ultrafiltration membrane in the retention of proteins
NASA Astrophysics Data System (ADS)
Jayalakshmi, A.; Rajesh, S.; Mohan, D.
Epoxidated polyethersulfone (EPES) incorporated cellulose acetate (CA) ultrafiltration membranes were prepared by diffusion induced precipitation technique in the absence and presence of pore former polyethyleneglycol-600. Effect of blend ratio on the compatibility, thermal stability, mechanical strength, hydrophilicity, morphology, pure water flux, protein adsorption resistance, protein separation efficiency and fouling propensity of the CA/EPES blend membranes was evaluated. Addition of EPES results in the formation of thin separating layer and spongy sub layer in CA/EPES blend membranes. The efficiency of these membranes in the separation of commercially important proteins such as bovine serum albumin, egg albumin, pepsin and trypsin was studied and found to be enhanced as compared to CA membranes. The fouling-resistant capability of the membranes was studied by bovine serum albumin as the model foulant and flux recovery ratio of the membranes were calculated. Attempts have been made to correlate the changes in membrane morphology with pure water flux, hydraulic resistance, thermal and mechanical stability, separation efficiency and antifouling property of the CA/EPES membranes. The optimal combination of CA and EPES, thus allows the preparation of high performance UF membranes which are sufficiently dense to retain proteins and at the same time give economically viable fluxes.
Lithium Dodecyl Sulfate\\/Polyacrylamide Gel Electrophoresis of Thylakoid Membranes at 4 degrees C: Characterizations of Two Additional Chlorophyll A-Protein Complexes
Philippe Delepelaire; Nam-Hai Chua
Lithium dodecyl sulfate\\/polyacrylamide gel electrophoresis of Chlamydomonas reinhardtii thylakoid membranes at room temperature gave two chlorophyll-protein complexes, CP I and CP II, as had been reported previously. However, when the electrophoresis was performed at 4 degrees C, there was an increase in the amount of chlorophyll associated with CP I and CP II, and in addition, three other chlorophyll-protein complexes
Magnetic Targeted Delivery of Dexamethasone Acetate across the Round Window Membrane in Guinea Pigs
Du, Xiaoping; Chen, Kejian; Kuriyavar, Satish; Kopke, Richard D.; Grady, Brian P.; Bourne, David H.; Li, Wei; Dormer, Kenneth J.
Hypothesis Magnetically susceptible PLGA nanoparticles will effectively target the round window membrane (RWM) for delivery of dexamethasone-acetate (Dex-Ac) to the scala tympani. Background Targeted delivery of therapeutics to specific tissues can be accomplished using different targeting mechanisms. One technology includes iron oxide nanoparticles, susceptible to external magnetic fields. If a nanocomposite composed of biocompatible polymer (PLGA), magnetite, and Dex-Ac can be pulled into and across the mammalian RWM, drug delivery can be enhanced. Method In vitro targeting and release kinetics of PLGA-magnetite-Dex-Ac nanoparticles first were measured using a RWM model. Next, these optimized nanocomposites were targeted to the RWM by filling the niche in anesthetized guinea pigs. A permanent magnet was placed opposite the RWM for 1 hour. Cochlear soft tissues, perilymph, and RWM were harvested after euthanasia and steroid levels were measured using HPLC. Results Membrane transport, in vitro, proved optimal targeting using a lower particle magnetite concentration (1 versus 5 or 10 mg/ml). In vivo targeted PLGA-magnetite-Dex-Ac particles had an average size of 482.8 � 158 nm (DLS) and an average zeta potential ?19.9 � 3.3 mV. In 1 hour, there was significantly increased cochlear targeted delivery of Dex or Dex-Ac, compared with diffusion alone. Conclusion Superparamagnetic PLGA-magnetite-Dex-Ac nanoparticles under an external magnetic field (0.26 mT) for 1 hour significantly increased Dex-Ac delivery to the inner ear. The RWM was not completely permeated and also became loaded with nanocomposites, indicating that delivery to the cochlea would continue for weeks by PLGA degradation and passive diffusion. PMID:23187928
Two-dimensional SDS-polyacrylamide gel electrophoresis of heat-modifiable outer-membrane proteins.
Russell, R R
An examination has been made of the effect which temperature of solubilization has upon the subsequent migration in SDS-polyacrylamide gel electrophoresis of proteins from the cell envelopes of Escherichia coli K12 and Neisseria sicca ATCC 9913. Conventional electrophoresis in tubes revealed substantial differences in the staining patterns of gels, depending upon whether the envelope samples were solubilized at 37 degrees C or 100 degrees C; in the case of N. sicca at least 6 of 13 discernible bands displayed heat-modifiable behavior. The relationship of the bands produced by each of the two temperatures was investigated by a two-dimensional electrophoresis procedure, in which a sample was solubilized at 37 degrees C and run in a usual cylindrical gel; the entire gel was then resolubilized at 100 degrees C, and laid along an acrylamide slab for electrophoresis in the second dimension. It was found that "free endotoxin" of both organisms examined contained the same major proteins as the total envelope fraction, and that these free endotoxin proteins showed the same heat-modifiable properties as when present in total envelopes. PMID:1252992
Facile fouling resistant surface modification of microfiltration cellulose acetate membranes by using amino acid L-DOPA.
Azari, Sara; Zou, Linda; Cornelissen, Emile; Mukai, Yasushito
A major obstacle in the widespread application of microfiltration membranes in the wet separation processes such as wastewater treatment is the decline of permeates flux as a result of fouling. This study reports on the surface modification of cellulose acetate (CA) microfiltration membrane with amino acid L-3,4-dihydroxy-phenylalanine (L-DOPA) to improve fouling resistance of the membrane. The membrane surface was characterised using Fourier transform infrared spectroscopy (FTIR), water contact angle and zeta potential measurement. Porosity measurement showed a slight decrease in membrane porosity due to coating. Static adsorption experiments revealed an improved resistance of the modified membranes towards the adhesion of bovine serum albumin (BSA) as the model foulant. Dead end membrane filtration tests exhibited that the fouling resistance of the modified membranes was improved. However, the effect of the modification depended on the foulant solution concentration. It is concluded that L-DOPA modification is a convenient and non-destructive approach to enable low-BSA adhesion surface modification of CA microfiltration membranes. Nevertheless, the extent of fouling resistance improvement depends on the foulant concentration. PMID:23985522
In situ hydrogen utilization for high fraction acetate production in mixed culture hollow-fiber membrane biofilm reactor.
Zhang, Fang; Ding, Jing; Shen, Nan; Zhang, Yan; Ding, Zhaowei; Dai, Kun; Zeng, Raymond J
Syngas fermentation is a promising route for resource recovery. Acetate is an important industrial chemical product and also an attractive precursor for liquid biofuels production. This study demonstrated high fraction acetate production from syngas (H? and CO?) in a hollow-fiber membrane biofilm reactor, in which the hydrogen utilizing efficiency reached 100% during the operational period. The maximum concentration of acetate in batch mode was 12.5 g/L, while the acetate concentration in continuous mode with a hydraulic retention time of 9 days was 3.6 � 0.1 g/L. Since butyrate concentration was rather low and below 0.1 g/L, the acetate fraction was higher than 99% in both batch and continuous modes. Microbial community analysis showed that the biofilm was dominated by Clostridium spp., such as Clostridium ljungdahlii and Clostridium drakei, the percentage of which was 70.5%. This study demonstrates a potential technology for the in situ utilization of syngas and valuable chemical production. PMID:24196583
Performance of cellulose acetate - polyethersulphone blend membrane prepared using microwave heating for palm oil mill effluent treatment.
Idris, A; Ahmed, I; Jye, H W
The objective of this research is to investigate the performance of blend cellulose acetate (CA)-polyethersulphone (PES) membranes prepared using microwave heating (MWH) techniques and then compare it with blend CA-PES membranes prepared using conventional heating (CH) methods using bovine serum albumin solution. The superior membranes were then used in the treatment of palm oil mill effluent (POME). Various blends of CA-PES have been blended with PES in the range of 1-5 wt%. This distinctive series of dope formulations of blend CA/PES and pure CA was prepared using N, N-dimethylformamide (DMF) as solvent. The dope solution was prepared by MW heating for 5 min at a high pulse and the membranes were prepared by phase inversion method. The performances of these membranes were evaluated in terms of pure water and permeate flux, percentage removal of total suspended solids (TSS), chemical oxygen demand (COD) and biochemical oxygen demand (BOD). The results indicate that blend membranes prepared using the microwave technique is far more superior compared to that prepared using CH. Blend membranes with 19% CA, 1-3% PES and 80% of DMF solvent were found to be the best membrane formulation. PMID:17978445
Quantifying contribution of synthrophic acetate oxidation to methane production in thermophilic anaerobic reactors by membrane inlet mass spectrometry.
Mulat, Daniel Girma; Ward, Alastair James; Adamsen, Anders Peter S; Voigt, Niels Vinther; Nielsen, Jeppe Lund; Feilberg, Anders
A unique method was developed and applied for monitoring methanogenesis pathways based on isotope labeled substrates combined with online membrane inlet quadrupole mass spectrometry (MIMS). In our study, a fermentation sample from a full-scale biogas plant fed with pig and cattle manure, maize silage, and deep litter was incubated with 100 mM of [2-(13)C] sodium acetate under thermophilic anaerobic conditions. MIMS was used to measure the isotopic distribution of dissolved CO2 and CH4 during the degradation of acetate, while excluding interference from water by applying a cold trap. After 6 days of incubation, the proportion of methane derived from reduction of CO2 had increased significantly and reached up to 87% of total methane, suggesting that synthrophic acetate oxidation coupled to hydrogenotrophic methanogenesis (SAO-HM) played an important role in the degradation of acetate. This study provided a new approach for online quantification of the relative contribution of methanogenesis pathways to methane production with a time resolution shorter than one minute. The observed contribution of SAO-HM to methane production under the tested conditions challenges the current widely accepted anaerobic digestion model (ADM1), which strongly emphasizes the importance of the acetoclastic methanogenesis. PMID:24437339
On-Chip Electrophoresis in Supported Lipid Bilayer Membranes Achieved Using Low Potentials
A micro supported lipid bilayer (SLB) electrophoresis method was developed, which functions at low potentials and appreciable operating times. To this end, (hydroxymethyl)-ferrocene (FcCH2OH) was employed to provide an electrochemical reaction at the anode and cathode at low applied potential to avoid electrolysis of water. The addition of FcCH2OH did not alter the SLB characteristics or affect biomolecule function, and pH and temperature variations and bubble formation were eliminated. Applying potentials of 0.25�1.2 V during flow gave homogeneous electrical fields and a fast, reversible, and strong build-up of a charged dye-modified lipid in the direction of the oppositely charged electrode. Moreover, streptavidin mobility could be modulated. This method paves the way for further development of analytical devices. PMID:24345193
Electrophoresis and isoelectric focusing of whole cell and membrane proteins from the extremely halophilic archaebacteria
NASA Technical Reports Server (NTRS)
Stan-Lotter, Helga; Lang, Frank J., Jr.; Hochstein, Lawrence I.
The subunits from two purified halobacterial membrane enzymes (ATPase and nitrate reductase) behaved differently with respect to isoelectric focusing, silver staining and interaction with ampholytes. Differential behavior was also observed in whole cell proteins from Halobacterium saccharovorum regarding resolution in two-dimensional gels and silver staining. It is proposed that these differences reflect the existence of two classes of halobacterial proteins.
Diffusive transfer to membranes as an effective interface between gel electrophoresis and mass spectrometry
NASA Astrophysics Data System (ADS)
Ogorzalek Loo, Rachel R.; Mitchell, Charles; Stevenson, Tracy I.; Loo, Joseph A.; Andrews, Philip C.
Diffusive transfer was examined as a blotting method to transfer proteins from polyacrylamide gels to membranes for ultraviolet matrix-assisted laser desorption ionization (MALDI) mass spectrometry. The method is well-suited for transfers from isoelectric focusing (IEF) gels. Spectra have been obtained for 11 pmol of 66 kDa albumin loaded onto an IEF gel and subsequently blotted to polyethylene. Similarly, masses of intact carbonic anhydrase and hemoglobin were obtained from 14 and 20 pmol loadings. This methodology is also compatible with blotting high molecular weight proteins, as seen for 6 pmol of the 150 kDa monoclonal antibody anti-[beta]-galactosidase transferred to Goretex. Polypropylene, Teflon, Nafion and polyvinylidene difluoride (PVDF) also produced good spectra following diffusive transfer. Only analysis from PVDF required that the membrane be kept wet prior to application of matrix. Considerations in mass accuracy for analysis from large-area membranes with continuous extraction and delayed extraction were explored, as were remedies for surface charging. Vapor phase CNBr cleavage was applied to membrane-bound samples for peptide mapping.
Membrane applications to coal conversion processes. Final report, June 1975September 1976. [Cellulose acetate, polysulfone
W. J. Schell; R. W. Lawrence; W. M. King
A survey of coal conversion processes was conducted to determine the appropriate application of membrane gas separation methods. This study included a review of gas stream compositions, pressures and temperatures, the application of membrane treatment to these gas streams, and comparisons with other commercial separation processes that may be comparable to membrane separation. It was determined that the SYNTHOIL, HYDRANE
Supported Lipid Bilayer Electrophoresis: A New Paradigm in Membrane Biophysics and Separations
Pace, Hudson 1982-
in allowing researchers to further add to mankind?s understanding of the cellular membrane. iv DEDICATION The last 5 years have been quite the journey and while the destination is all that I had ever hoped for, it was the path to this point that I... for my committee. As in any arduous journey, a bond has been forged between the peers whom I have shared this path with. Mike, I could not have asked for a better roommate during my years in grad school. Aaron, you always made work a more enjoyable...
Biomass fermentation produces ethanol and other renewable biofuels. Pervaporation using hydrophobic membranes is potentially a cost-effective means of removing biofuels from fermentation broths for small- to medium-scale applications. Silicalite-filled polydimethylsiloxane (PDMS)...
Removal of chromium from aqueous solution using cellulose acetate and sulfonated poly(ether ether ketone) blend ultrafiltration membranes.
Arthanareeswaran, G; Thanikaivelan, P; Jaya, N; Mohan, D; Raajenthiren, M
A process for purifying aqueous solutions containing heavy and toxic metals such as chromium has been investigated. Chromium salts are largely used in various industries including leather-manufacturing industry. Ultrafiltration processes are largely being applied for macromolecular and heavy metal ion separation from aqueous streams. Cellulose acetate and sulfonated poly(ether ether ketone) blend ultrafiltration membranes were prepared by precipitation phase inversion technique in 100/0, 90/10, 80/20 and 70/30% polymer blend compositions and subjected to the rejection of chromium at different concentrations such as 200, 400, 600, 800 and 1000 ppm with a water-soluble macroligand (polyvinylalcohol). Factors affecting the percentage rejection and permeate flux such as pH, concentration of solute, concentration of PVA, transmembrane pressure and composition of blend membranes were investigated. It was found that percentage rejection improved at a pH 6 and a macroligand concentration of 2 wt.%. The transmembrane pressure and concentration of solute also have an effect on the separation and product rate efficiencies of the blend membranes. PMID:16860465
Estimation of the uptake rate constants for polycyclic aromatic hydrocarbons accumulated by semipermeable membrane devices and triolein-embedded cellulose acetate membranes.
Ke, Runhui; Xu, Yiping; Wang, Zijian; Khan, Shahamat U
In this paper we report an extension of our previous work on the triolein-embedded cellulose acetate membrane (TECAM) as a passive sampling device (PSD) and describe the results from simultaneous exposure of TECAMs and triolein-containing semipermeable membrane devices (SPMDs) to PAHs in lake water for 16 days. The data obtained provided a comparison of the uptake rates of specific PAHs by the two PSDs. Using 16-day accumulation tests, similar PAH distribution patterns in TECAMs and in SPMDs (R2 = 0.89, p < 0.0001) were observed. However, it was noted that TECAMs could take up greater amounts of PAHs than SPMDs (735 ng/g of TECAM vs 630 ng/g of SPMD). Uptake rate constants of TECAMs and SPMDs for 16 priority pollutant (PP) PAHs, corrected for dissolved organic carbon, ranged from 0.28 to 2.94 L d(-1) and from 0.16 to 0.91 L d(-1), respectively. The elimination rate constants of TECAMs were 1.4-6.7 times greater than those observed for SPMDs, thereby indicating that PAHs required shorter times to achieve equilibrium in TECAMs than in SPMDs. Thus, the results of the present study suggest that TECAMs have significant potential as a good monitor to assess the pollution of hydrophobic pollutants in aquatic environments. PMID:16830560
NSDL National Science Digital Library
In this activity, learners follow step-by-step instructions to build a gel electrophoresis chamber using inexpensive materials from local hardware and electronic stores. Then, learners follow instructions to simulate DNA electrophoresis using food colors from the kitchen pantry.
Nanofiltration of model acetate solutions
I. S. Han; M. Cheryan
Several nanofiltration and reverse osmosis membranes were screened for separating acetic acid from model solutions. Flux increased with pressure and temperature and decreased with pH and concentration of acetate. Rejection increased with pH, probably depending on the degree of dissociation of the acetate. At higher pH, acetate rejection could be correlated with NaCl rejection. Of all the membranes screened, the
Plasticizer effect and comparative evaluation of cellulose acetate and ethylcellulose-HPMC combination coatings as semipermeable membranes for oral osmotic pumps of naproxen sodium.
Ramakrishna, N; Mishra, B
The objective of this study was to compare the performance of cellulose acetate (CA) and ethylcellulose (EC)-HPMC combination coatings as semipermeable membranes (SPMs) for osmotic pump tablets (OPTs) of naproxen sodium (NPS) so as to deliver a constant, predetermined amount of drug in solution form over a fixed span of time, independent of external environmental conditions. Osmotic pump tablets were designed with different coating variables and optimized in terms of nature of plasticizer, membrane thickness, and orifice diameter. The effect of insertion of an inner microporous film around the NPS core to minimize deformation of the SPM due to peristaltic movement of the gut was also studied. Osmotic pump tablets composed of membranes with water-soluble plasticizer, propyleneglycol (PG), released drug mainly through diffusion, whereas those designed with CA and EC-HPMC (4:1) coats containing water-insoluble plasticizer, castor oil, released their contents by perfect zero-order kinetics over a prolonged period of time, though the average release rate that could be achieved with the EC-HPMC (4:1) membrane was only about half the rate achieved with the CA membrane for the same membrane thickness. Release rates for both the membranes decreased with increasing membrane thickness and were found to be independent of orifice diameter, agitation intensity, and pH of the dissolution medium. PMID:12056533
Electrophoresis-enhanced detection of deoxyribonucleic acids on a membrane-based lateral flow strip using avian influenza H5 genetic sequence as the model.
Wu, Jui-Chuang; Chen, Chih-Hung; Fu, Ja-Wei; Yang, Huan-Ching
This study reports a simple strategy to detect a deoxyribonucleic acid (DNA) on a membrane-based lateral flow (MBLF) strip without tedious gel preparation, gel electrophoresis, and EtBr-staining processes. The method also enhances the detection signal of the genetic sample. A direct electric field was applied over two ends of the MBLF strips to induce an electrophoresis of DNAs through the strips. The signal enhancement was demonstrated by the detection of the H5 subtype of avian influenza virus (H5 AIV). This approach showed an excellent selectivity of H5 AIV from other two control species, Arabidopsis thaliana and human PSMA5. It also showed an effective signal repeatability and sensitivity over a series of analyte concentrations. Its detection limit could be enhanced, from 40 ng to 0.1 ng by applying 12 V. The nano-gold particles for the color development were labeled on the capture antibody, and UV-VIS and TEM were used to check if the labeling was successful. This detection strategy could be further developed to apply on the detection of drug-allergic genes at clinics or detection of infectious substances at incident sites by a simple manipulation with an aid of a mini-PCR machine and auxiliary kits. PMID:24603637
Electrophoresis-Enhanced Detection of Deoxyribonucleic Acids on a Membrane-Based Lateral Flow Strip Using Avian Influenza H5 Genetic Sequence as the Model
Wu, Jui-Chuang; Chen, Chih-Hung; Fu, Ja-Wei; Yang, Huan-Ching
This study reports a simple strategy to detect a deoxyribonucleic acid (DNA) on a membrane-based lateral flow (MBLF) strip without tedious gel preparation, gel electrophoresis, and EtBr-staining processes. The method also enhances the detection signal of the genetic sample. A direct electric field was applied over two ends of the MBLF strips to induce an electrophoresis of DNAs through the strips. The signal enhancement was demonstrated by the detection of the H5 subtype of avian influenza virus (H5 AIV). This approach showed an excellent selectivity of H5 AIV from other two control species, Arabidopsis thaliana and human PSMA5. It also showed an effective signal repeatability and sensitivity over a series of analyte concentrations. Its detection limit could be enhanced, from 40 ng to 0.1 ng by applying 12 V. The nano-gold particles for the color development were labeled on the capture antibody, and UV-VIS and TEM were used to check if the labeling was successful. This detection strategy could be further developed to apply on the detection of drug-allergic genes at clinics or detection of infectious substances at incident sites by a simple manipulation with an aid of a mini-PCR machine and auxiliary kits. PMID:24603637
Removal of pesticides and other micropollutants with cellulose-acetate, polyamide and ultra-low pressure reverse osmosis membranes
J. A. M. H. Hofman; E. F. Beerendonk; H. C. Folmer; J. C. Kruithof
In 1995 several membrane manufacturers started to sell ultra low-pressure reverse osmosis membranes. The specifications of these membranes indicated that they have rejections for dissolved salts comparable to �conventional� composite (polyamide) membranes, while the required feed pressure to realize a specific production capacity is 30�40% less. This article describes the results of a preliminary study on the performance of these
Antibody response to epitopes of chlamydial major outer membrane proteins on infectious elementary bodies and of the reduced polyacrylamide gel electrophoresis-separated form.
Baghian, A; Shaffer, L; Storz, J
Approximately 60% of the outer membrane of chlamydial elementary bodies (EBs) consists of the major outer membrane protein (MOMP) that has structural and metabolic functions. The antigenic properties of MOMPs from mammalian strains of serovars 1 and 2 and an avian strain of Chlamydia psittaci were analyzed. Polyclonal-monospecific antisera (PMAs), one monoclonal antibody (MAb), and polyclonal antisera (PAs) were produced against reduced polyacrylamide gel electrophoresis-separated MOMPs and against infectious EBs. Three PMAs and the MAb, which were induced by reduced polyacrylamide gel electrophoresis-separated MOMPs, reacted strongly in Western blot (immunoblot) assays with MOMPs of serovar 1 and 2 strains as well as with that of the avian strain 6BC, and two of these PMAs reacted weakly (dilution, 1:20) with the MOMP of strain LGV-2. The third PMA and the MAb against the MOMP of the serovar 2 strain did not react with the MOMP of LGV-2. Four PAs were produced against infectious EBs of the serovar 1 strain. One of these PAs reacted with the homologous MOMP and that of the avian strain 6BC but did not recognize MOMPs of other chlamydial strains. Three of the PAs reacted with MOMPs of homologous strains only and failed to recognize MOMPs of avian, serovar 2, and LGV-2 strains. Five PAs induced against infectious EBs of the serovar strain 2 reacted only with the MOMPs of the homologous strains and failed to recognize MOMPs of other strains of chlamydiae. Consequently, MOMPs of C. psittaci strains possess genus-, species-, and serovar-specific epitopes whereby the immune response to serovar-specific epitopes of MOMP predominate when infectious EBs are used for immunization. Images PMID:1691145
ERIC Educational Resources Information Center
Maderia, Vitor M. C.; Pires, Euclides M. V.
Discusses the value of electrophoresis in the fields of protein chemistry and biochemistry. Describes how to build an inexpensive electrophoresis setup for use in either research or teaching activities. Details the construction of both the separating device and the power supply. (TW)
Gypsum (CaSO4�2H2O) Scaling on Polybenzimidazole and Cellulose Acetate Hollow Fiber Membranes under Forward Osmosis
Chen, Si Cong; Su, Jincai; Fu, Feng-Jiang; Mi, Baoxia; Chung, Tai-Shung
We have examined the gypsum (CaSO4�2H2O) scaling phenomena on membranes with different physicochemical properties in forward osmosis (FO) processes. Three hollow fiber membranes made of (1) cellulose acetate (CA), (2) polybenzimidazole (PBI)/polyethersulfone (PES) and (3) PBI-polyhedral oligomeric silsesquioxane (POSS)/polyacrylonitrile (PAN) were studied. For the first time in FO processes, we have found that surface ionic interactions dominate gypsum scaling on the membrane surface. A 70% flux reduction was observed on negatively charged CA and PBI membrane surfaces, due to strong attractive forces. The PBI membrane surface also showed a slightly positive charge at a low pH value of 3 and exhibited a 30% flux reduction. The atomic force microscopy (AFM) force measurements confirmed a strong repulsive force between gypsum and PBI at a pH value of 3. The newly developed PBI-POSS/PAN membrane had ridge morphology and a contact angle of 51.42� � 14.85� after the addition of hydrophilic POSS nanoparticles and 3 min thermal treatment at 95 �C. Minimal scaling and an only 1.3% flux reduction were observed at a pH value of 3. Such a ridge structure may reduce scaling by not providing a locally flat surface to the crystallite at a pH value of 3; thus, gypsum would be easily washed away from the surface. PMID:24957062
Gypsum (CaSO4�2H2O) Scaling on Polybenzimidazole and Cellulose Acetate Hollow Fiber Membranes under Forward Osmosis.
Chen, Si Cong; Su, Jincai; Fu, Feng-Jiang; Mi, Baoxia; Chung, Tai-Shung
We have examined the gypsum (CaSO4�2H2O) scaling phenomena on membranes with different physicochemical properties in forward osmosis (FO) processes. Three hollow fiber membranes made of (1) cellulose acetate (CA), (2) polybenzimidazole (PBI)/polyethersulfone (PES) and (3) PBI-polyhedral oligomeric silsesquioxane (POSS)/polyacrylonitrile (PAN) were studied. For the first time in FO processes, we have found that surface ionic interactions dominate gypsum scaling on the membrane surface. A 70% flux reduction was observed on negatively charged CA and PBI membrane surfaces, due to strong attractive forces. The PBI membrane surface also showed a slightly positive charge at a low pH value of 3 and exhibited a 30% flux reduction. The atomic force microscopy (AFM) force measurements confirmed a strong repulsive force between gypsum and PBI at a pH value of 3. The newly developed PBI-POSS/PAN membrane had ridge morphology and a contact angle of 51.42� � 14.85� after the addition of hydrophilic POSS nanoparticles and 3 min thermal treatment at 95 �C. Minimal scaling and an only 1.3% flux reduction were observed at a pH value of 3. Such a ridge structure may reduce scaling by not providing a locally flat surface to the crystallite at a pH value of 3; thus, gypsum would be easily washed away from the surface. PMID:24957062
Pervaporation is a potential process for recovering bioethanol produced from biomass fermentation. Fermentation broths contain ethanol, water, and a variety of other compounds, often including carboxylic acids. The effects of acetic acid on long-term pervaporation of aqueous et...
Analysis of electrophoresis performance
NASA Technical Reports Server (NTRS)
Roberts, G. O.
The SAMPLE computer code models electrophoresis separation in a wide range of conditions. Results are included for steady three dimensional continuous flow electrophoresis (CFE), time dependent gel and acetate film experiments in one or two dimensions and isoelectric focusing in one dimension. The code evolves N two dimensional radical concentration distributions in time, or distance down a CFE chamber. For each time or distance increment, there are six stages, successively obtaining the pH distribution, the corresponding degrees of ionization for each radical, the conductivity, the electric field and current distribution, and the flux components in each direction for each separate radical. The final stage is to update the radical concentrations. The model formulation for ion motion in an electric field ignores activity effects, and is valid only for low concentrations; for larger concentrations the conductivity is, therefore, also invalid.
Synthesis and Characterisation of ETS-10/Acetate-based Ionic Liquid/Chitosan Mixed Matrix Membranes for CO2/N2 Permeation
Casado-Coterillo, Clara; L�pez-Guerrero, Mar�a del Mar; Irabien, �ngel
Mixed matrix membranes (MMMs) were prepared by incorporating organic surfactant-free hydrothermally synthesised ETS-10 and 1-ethyl-3-methylimidazolium acetate ionic liquid (IL) to chitosan (CS) polymer matrix. The membrane material characteristics and permselectivity performance of the two-component membranes were compared with the three-component membrane and the pure CS membrane. The addition of IL increased CO2 solubility of the polymer, and, thus, the CO2 affinity was maintained for the MMMs, which can be correlated with the crystallinity, measured by FT-IR, and void fraction calculations from differences between theoretical and experimental densities. The mechanical resistance was enhanced by the ETS-10 nanoparticles, and flexibility decreased in the two-component ETS-10/CS MMMs, but the flexibility imparted by the IL remained in three-component ETS-10/IL/CS MMMs. The results of this work provide insight into another way of facing the adhesion challenge in MMMs and obtain CO2 selective MMMs from renewable or green chemistry materials. PMID:24957178
NSDL National Science Digital Library
This interactive activity from the Dolan DNA Learning Center illustrates the process of gel electrophoresis, in which DNA fragments are separated by size as they migrate at different rates through a gel matrix.
NSDL National Science Digital Library
In the early days of DNA manipulation, DNA fragments were laboriously separated by gravity. In the 1970s, the powerful tool of DNA gel electrophoresis was developed. This process uses electricity to separate DNA fragments by size as they migrate through a gel matrix. This animation from Cold Spring Harbor Laboratory's Dolan DNA Learning Center presents Gel Electrophoresis through a series of illustrations of the processes involved.
Exploitation of detergent thermodynamics in the direct solubilization of myelin membrane proteins for two-dimensional gel electrophoresis for proteomic analysis.
Nair, Sreepriya; Xavier, Tessy; Kumar, Madathiparambil Kumaran Satheesh; Saha, Sharmistha; Menon, Krishnakumar N
Performing 2-DE of lipid-rich multilamellar membranes like myelin is a cumbersome task. However, for understanding its molecular organization and changes during diseases, identification of proteins of myelin is essential. Although the 2-D-proteomic approach of myelin has been employed to understand the myelin proteome, representation of myelin proteins in its entirety is still a challenge. 2-DE profiling of myelin proteins is very important for the detection of immuno-reactivity to myelin proteins from various biological fluids following Western blotting in diseases like multiple sclerosis. Here we developed a novel approach by exploiting the thermodynamic principles behind detergent-mediated solubilization of myelin membranes without any conventional processing of myelin involving precipitation of myelin proteins. We show that the addition of myelin to ASB-14-4 resulted in significant increase in protein representation of myelin in 2-DE compared with the addition of ASB-14-4 to myelin. Moreover, the number and resolution of spots are significantly higher in myelin to ASB-14-4 strategy than other strategies of myelin sample processing such as ASB-14-4 to myelin or ethanol or acetone or methanol-ammonium acetate precipitation of myelin proteins. In addition, the step involves no precipitation that selective removal of any proteins as a result of precipitation is nil and a qualitative representation of myelin proteins in a 2-D gel is achieved. PMID:22102008
Characterization of a direct effect of phorbol myristate acetate on human neutrophil cell membrane using 31D8 monoclonal antibody
Charles L. Woronick; Eufronio G. MaderazotS; Monique N. AnthonyPeter; J. Krause; Ramadan I. Sha
We found that 4-13-phorbol 12-myristate 13-acetate (PMA) caused decreased expression of the polymorphonuclear neutrophil (PMN) surface antigen 31D8. In contrast to the rapid initiation of the oxidative burst caused by PMA, the effect was slow to start but in- creased during incubation periods up to 50 mm. To study this apparent protein kinase C-independent late effect of PMA, we measured
Parallel characterization of anaerobic toluene- and ethylbenzene-degrading microbial consortia by PCR-denaturing gradient gel electrophoresis, RNA-DNA membrane hybridization, and DNA microarray technology
NASA Technical Reports Server (NTRS)
Koizumi, Yoshikazu; Kelly, John J.; Nakagawa, Tatsunori; Urakawa, Hidetoshi; El-Fantroussi, Said; Al-Muzaini, Saleh; Fukui, Manabu; Urushigawa, Yoshikuni; Stahl, David A.
A mesophilic toluene-degrading consortium (TDC) and an ethylbenzene-degrading consortium (EDC) were established under sulfate-reducing conditions. These consortia were first characterized by denaturing gradient gel electrophoresis (DGGE) fingerprinting of PCR-amplified 16S rRNA gene fragments, followed by sequencing. The sequences of the major bands (T-1 and E-2) belonging to TDC and EDC, respectively, were affiliated with the family Desulfobacteriaceae. Another major band from EDC (E-1) was related to an uncultured non-sulfate-reducing soil bacterium. Oligonucleotide probes specific for the 16S rRNAs of target organisms corresponding to T-1, E-1, and E-2 were designed, and hybridization conditions were optimized for two analytical formats, membrane and DNA microarray hybridization. Both formats were used to characterize the TDC and EDC, and the results of both were consistent with DGGE analysis. In order to assess the utility of the microarray format for analysis of environmental samples, oil-contaminated sediments from the coast of Kuwait were analyzed. The DNA microarray successfully detected bacterial nucleic acids from these samples, but probes targeting specific groups of sulfate-reducing bacteria did not give positive signals. The results of this study demonstrate the limitations and the potential utility of DNA microarrays for microbial community analysis.
Parallel Characterization of Anaerobic Toluene- and Ethylbenzene-Degrading Microbial Consortia by PCR-Denaturing Gradient Gel Electrophoresis, RNA-DNA Membrane Hybridization, and DNA Microarray Technology
Koizumi, Yoshikazu; Kelly, John J.; Nakagawa, Tatsunori; Urakawa, Hidetoshi; El-Fantroussi, Sa�d; Al-Muzaini, Saleh; Fukui, Manabu; Urushigawa, Yoshikuni; Stahl, David A.
A mesophilic toluene-degrading consortium (TDC) and an ethylbenzene-degrading consortium (EDC) were established under sulfate-reducing conditions. These consortia were first characterized by denaturing gradient gel electrophoresis (DGGE) fingerprinting of PCR-amplified 16S rRNA gene fragments, followed by sequencing. The sequences of the major bands (T-1 and E-2) belonging to TDC and EDC, respectively, were affiliated with the family Desulfobacteriaceae. Another major band from EDC (E-1) was related to an uncultured non-sulfate-reducing soil bacterium. Oligonucleotide probes specific for the 16S rRNAs of target organisms corresponding to T-1, E-1, and E-2 were designed, and hybridization conditions were optimized for two analytical formats, membrane and DNA microarray hybridization. Both formats were used to characterize the TDC and EDC, and the results of both were consistent with DGGE analysis. In order to assess the utility of the microarray format for analysis of environmental samples, oil-contaminated sediments from the coast of Kuwait were analyzed. The DNA microarray successfully detected bacterial nucleic acids from these samples, but probes targeting specific groups of sulfate-reducing bacteria did not give positive signals. The results of this study demonstrate the limitations and the potential utility of DNA microarrays for microbial community analysis. PMID:12088997
A difference gel electrophoresis study on thylakoids isolated from poplar leaves reveals a negative impact of ozone exposure on membrane proteins.
Bohler, Sacha; Sergeant, Kjell; Hoffmann, Lucien; Dizengremel, Pierre; Hausman, Jean-Francois; Renaut, Jenny; Jolivet, Yves
Populus tremula L. x P. alba L. (Populus x canescens (Aiton) Smith), clone INRA 717-1-B4, saplings were subjected to 120 ppb ozone exposure for 28 days. Chloroplasts were isolated, and the membrane proteins, solubilized using the detergent 1,2-diheptanoyl-sn-glycero-3-phosphocholine (DHPC), were analyzed in a difference gel electrophoresis (DiGE) experiment comparing control versus ozone-exposed plants. Extrinsic photosystem (PS) proteins and adenosine triphosphatase (ATPase) subunits were detected to vary in abundance. The general trend was a decrease in abundance, except for ferredoxin-NADP(+) oxidoreductase (FNR), which increased after the first 7 days of exposure. The up-regulation of FNR would increase NAPDH production for reducing power and detoxification inside and outside of the chloroplast. Later on, FNR and a number of PS and ATPase subunits decrease in abundance. This could be the result of oxidative processes on chloroplast proteins but could also be a way to down-regulate photochemical reactions in response to an inhibition in Calvin cycle activity. PMID:21520910
technical manual protein electrophoresis
Kirschner, Marc W.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Chapter 2 Polyacrylamide Gel Electrophoresis.2 Separating proteins on the basis of molecular weight: SDS gel electrophoresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 2.5 Native gel electrophoresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 2
Proton-transport activity, sidedness, and morphometry of tonoplast and plasma-membrane vesicles purified by free-flow electrophoresis from roots of Lepidium sativum L. and hypocotyls of Cucurbita pepo L
G�nther F. E. Scherer; Barbara Dorp; Claudia Sch�llmann; Dieter Volkmann
Large-scale preparations of highly purified tonoplast and plasma-membrane vesicles were obtained from roots (garden cress, Lepidium sativum L.) and shoots (etiolated zucchini hypocotyl, Cucurbita pepo L.) of representative dicotyledonous seedlings. When tonoplast-enriched fractions of cress roots were prepared by centrifugation and then subjected to free-flow electrophoresis a highly purified tonoplast fraction was obtained. This fraction from cress roots was characterized
ERIC Educational Resources Information Center
Moertel, Cheryl; Frutiger, Bruce
Describes a DNA fingerprinting simulation that uses vegetable food coloring and plastic food containers instead of DNA and expensive gel electrophoresis chambers. Allows students to decipher unknown combinations of dyes in a method similar to that used to decipher samples of DNA in DNA fingerprint techniques. (JRH)
NSDL National Science Digital Library
Julie Yu
In this activity, learners simulate the process of DNA fingerprinting by using electricity to separate colored dyes. Learners use simple materials to assemble a comb (electrophoresis chamber) to hold the samples, make a 0.2% sodium bicarbonate buffer and 1% gel solution, connect a high voltage power supply, and prepare 5 different samples. Then learners test their model and observe each sample.
Pervaporation is potentially a cost-effective means of recovering biofuels, such as ethanol, from biomass fermentation broths for small- to medium-scale applications (~2 - 20 million liters per year). Hydrophobic zeolite-filled polydimethylsiloxane (PDMS) membranes have been sho...
Molecular imprinting of cellulose acetate-sulfonated polysulfone blend membranes for Rhodamine B by phase inversion technique
Malaisamy Ramamoorthy; Mathias Ulbricht
A functional polymer, sulfonated polysulfone (SPS) with a degree of substitution of 0.10, was prepared and then blended with cellulose diacetate (CA) as the matrix polymer for the preparation of molecularly imprinted polymer (MIP) membranes via phase inversion from a casting solution containing a template. Polyethylene glycol was found to be compatible with these polymers and was subsequently used as
Development of Low Cost Membranes (Ta, Nb & Cellulose Acetate) for H{sub 2}/CO{sub 2} Separation in WGS Reactors
Naidu Seetala; Upali Siriwardane
The main aim of this work is to synthesize low temperature bimetallic nanocatalysts for Water Gas Shift reaction (WGS) for hydrogen production from CO and steam mixture; and develop low-cost metal (Nb/Ta)/ceramic membranes for H{sub 2} separation and Cellulose Acetate membranes for CO{sub 2} separation. Cu-Ni-Ce/alumina, Fe-Ni-Ce/alumina granular WGS catalysts incorporating metal oxide nanoparticles into alumina support were prepared using sol-gel/oil-drop methods. The catalysts were characterized by Powder X-ray Diffractometer (PXRD), Scanning Electron Microscope (SEM), Differential Thermal Analyzer (DTA), Thermal Gravitational Analyzer (TGA), and Brunauer, Emmett and Teller (BET) techniques. TGA shows sharp weight loss at approximately 215°C and DTA shows dehydration of metal hydroxides between 200°C and 250°C. The PXRD spectra show an increase in crystallinity as a result of heating to 1000°C, and indicating a fine dispersion of the metal oxide nanoparticles in alumina supports during the sol-gel synthesis and calcination at 450°C. BET analysis indicated a mesoporous structure of the granules with high surface area. A gas-phase dynamic flow reactor is used to optimize the reaction temperatures. A gas-phase batch reactor was used to obtain kinetic data and the parameters for maximum CO conversion. In Cu-Ni-Ce/alumina category, Cu(0%)Ni(10%)Ce(11%) was found to be the best WGS catalyst among six Low Temperature Shift (LTS) catalysts with optimum temperatures between 200-300�?°C, while Ni(5%)Cu(5%)Ce(11%) was found to be the best among four High Temperature Shift (HTS) catalysts with optimum temperature between 350-400°C. In the Fe-Ni-Ce/alumina category catalysts, Fe(8%)Ni(0%)Ce(8%)/alumina and Fe(6%)Ni(2%)Ce(8%)/alumina catalysts showed optimum WGS reaction temperature below 150°C. All Ni(8-x%)Fe(x%)Ce(8%) had lower WGS reaction efficiencies compared to Ni(8-x%)Cu(x%)Ce(8%). Metal (Nb or Ta)/ceramic membranes for hydrogen separation from the WGS reaction gas products have been prepared using a) sputtering and b) aluminothermic techniques. A polyvinyl-glass permeability tester was used with a gas chromatograph (GC) for H{sub 2}/CO permeability testing. Nb films showed a higher permeability than Ta at a given disk porosity. The aluminothermically deposited membranes have higher H{sub 2} permeability compared to the sputtered films, and Nb-film coated disks showed lower H{sub 2} permeability than Ta-film. A three-stage prototype stainless steel reactor with integrated housing for 1) WGS reaction catalysts, 2) H{sub 2}/CO{sub 2} separation metal/ceramic or metal/asbestos membranes, and 3) CO/CO{sub 2} separation cellulose acetate /filter-paper membranes has been designed and tested to have capabilities to perform WGS reactions at temperatures up to 400°C and withstand gas pressures up to 15 bars. The cracking of ceramic disks and gas leaks were successfully prevented by replacing ceramic disks with asbestos sheets that can easily withstand 400°C. Kinetic studies of H{sub 2} and CO permeabilities were performed through the single and double layer Nb and Ta membranes. Cellulose acetate (CA) films with 25% triethyl citrate (TEC) as plasticizer were prepared for H{sub 2}/CO/CO{sub 2} gas separation with varying thickness of the films by acetone solutions at different concentrations and by dip-coating onto filter papers. The AFM analysis of the CA membrane showed that the uniform coating had fewer and smaller pores as the film thickness increased, and corroborated by gas permeability studies. The CO{sub 2} permeability has decreased faster than CO permeability with the CA/TEC membrane thickness, and findings support that the CA membrane could be used to entrap CO{sub 2}. Several CA/TEC membranes were also staked to increase the separation efficiency. Positron Lifetime Spectroscopy (PLS) was used to estimate the micro-porosity (pore size and concentration) and fractional free volume changes of CA/TEC films, and used to understand the variations observed in the CO{sub 2}/CO permeabilities.
Gordeeva, G.N.; Kalashnikov, S.M.; Popov, Yu.N.; Kruglov, E.A.; Imashev, U.B.
The treatment of methylglyoxal acetals by alkyl nitrites in the presence of the corresponding aliphatic alcohols and hydrochloric acid leads to the formation of linear mesoxalaldehyde acetals, whose structure was established by NMR spectroscopy and mass spectrometry. The major pathways for the decomposition of these molecules upon electron impact were established.
Fluid flow electrophoresis in space
NASA Technical Reports Server (NTRS)
Griffin, R. N.
Four areas relating to free-flow electrophoresis in space were investigated. The first was the degree of improvement over earthbound operations that might be expected. The second area of investigation covered the problems in developing a flowing buffer electrophoresis apparatus. The third area of investigation was the problem of testing on the ground equipment designed for use in space. The fourth area of investigation was the improvement to be expected in space for purification of biologicals. The results of some ground-based experiments are described. Other studies included cooling requirements in space, fluid sealing techniques, and measurement of voltage drop across membranes.
Electrophoresis. [in microgravity environment
NASA Technical Reports Server (NTRS)
Bier, M.
Ground-based techniques for electrophoresis take account of the need either to circumvent the effects of gravity to prevent convection, or to use gravity for fluid stabilization through artificial density gradients. The microgravity environments of orbiting spacecraft provides a new alternative for electrophoresis by avoiding the need for either of these two approaches. The paper presents some theoretical considerations concerning electrophoresis, examines certain experimental techniques (zone and high density gel electrophoresis, isoelectric focusing and isotachophoresis), and examines the electrophoresis of living cells.
NASA Technical Reports Server (NTRS)
Rhodes, P. H.; Snyder, R. S. (inventors)
A device for separating cellular particles of a sample substance into fractionated streams of different cellular species includes a casing having a distribution chamber, a separation chamber, and a collection chamber. The electrode chambers are separated from the separation chamber interior by means of passages such that flow variations and membrane variations around the slotted portion of the electrode chamber do not enduce flow perturbations into the laminar buffer curtain flowing in the separation chamber. The cellular particles of the sample are separated under the influence of the electrical field and the separation chamber into streams of different cellular species. The streams of separated cells enter a partition array in the collection chamber where they are fractionated and collected.
NASA Technical Reports Server (NTRS)
Todd, P.
A kidney cell electrophoresis technique is described in four parts: (1) the development and testing of electrophoresis solutions; (2) optimization of freezing and thawing; (3) procedures for evaluation of separated kidney cells; and (4) electrophoretic mobility characteristics of kidney cells.
NASA Technical Reports Server (NTRS)
Todd, P.
The following aspects of kidney cell electrophoresis are discussed: (1) the development and testing of electrophoresis solutions; (2) optimization of freezing and thawing; (3) procedures for evaluation of separated kidney cells; and (4) electrophoretic mobility characterization of kidney cells.
Protein electrophoresis - serum
This lab test measures the types of protein in the fluid (serum) part of a blood sample. Other electrophoresis tests that measure proteins in the serum include: Immunoelectrophoresis Immunofixation Globulin electrophoresis
An Economical Electrophoresis Apparatus
ERIC Educational Resources Information Center
Andrews, I. M.
Describes the production of an electrophoresis apparatus from commonly discarded articles. Outlines paper and gel electrophoresis and its application to the separation of amino acids and intestinal enzymes. (GS)
NASA Technical Reports Server (NTRS)
Todd, P. W.
Tasks were undertaken in support of two objectives. They are: (1) to carry out electrophoresis experiments on cells in microgravity; and (2) assess the feasibility of using purified kidney cells from embryonic kidney cultures as a source of important cell products. Investigations were carried out in the following areas: (1) ground based electrophoresis technology; (2) cell culture technology; (3) electrophoresis of cells; (4) urokinase assay research; (5) zero-g electrophoresis; and (6) flow cytometry.
Gel Electrophoresis and Photography
Simpson, Larry
Gel Electrophoresis and Photography An Application Note UVP-AB-1000-02 #12;The GDS-8000 Gel on the overlayed scan. GEL ELECTROPHORESIS IMAGING, DOCUMENTATION AND ANALYSIS ... TODAY. #12;The introduction of the technique of electrophoresis in acrylamide or agarose gels was a major advance in nucleic acid technology
Histone H4 N-Terminal Acetylation in Kasumi-1 Cells Treated with Depsipeptide Determined by Acetic Acid�Urea olyacrylamide Gel Electrophoresis, Amino Acid Coded Mass Tagging, and Mass Spectrometry
Zhang, Liwen; Su, Xiaodan; Liu, Shujun; Knapp, Amy R.; Parthun, Mark R.; Marcucci, Guido; Freitas, Michael A.
Disrupted patterns of acetylation and deacetylation of core histones play an important role in silencing transcription of hematopoietic important genes in acute myeloid leukemia (AML). A thorough investigation of these mechanisms and the response to pharmacologic modifiers will provide a better understanding of the role of histone acetylation in leukemogenesis. We describe here an analytical approach that combines acid urea polyacrylamide gel electrophoresis (AU-PAGE), amino acid coded mass tagging (AACM), and mass spectrometry (MS) for the investigation of histone acetylation patterns. The combined approach was used to follow the dynamics of H4 acetylation in Kasumi-1 cells harboring the fusion gene AML1/ETO shown to aberrantly recruit histone deacetylases (HDACs). The histones in Kasumi-1 cells were labeled by growing the cells in media in which lysine was replaced with stable isotope-labeled lysine (Lys-D4). Labeled and unlabeled cells were treated with depsipeptide and analyzed at different time points (0, 4, 8, 12, 24, and 48 h). The cells were mixed, the histone was extracted, and acetylated H4 isoforms were separated using AU-PAGE before in-gel trypsin digestion. The digests were analyzed by MALDI-TOF MS. Peptides were identified by mass and isotope pattern. LC�MS/MS of Arg-C digests were also performed to verify the acetylation pattern for H4. The major pattern of acetylation was determined as follows: initial acetylation at K16, followed by acetylation at K12, and finally acetylation of either K8 and/or K5. PMID:17203951
Phycocyanin from Chroomonas species purification, electrophoresis and isolation of subunits
Yao, Phyllis Ping-Ching
. Acrylamide Gel Electrophoresis. Isoelectric Focusing. Cyanogen Bromide Cleavage. Carboxymethylation of Phycocyanin. Amino Acid Analysis. Amino-terminal Analysis. Tryptic Digest Reverse Phase Thin Layer Chromatography. . UV-visible Absorption Spectra...CH pellets, was transferred with acetone-glacial acetic a. cid (p;2, v/v) to a polyamide sheet for two-dimentional 62 thin layer chromatography with solvent systems: (1) water- 90/o formic acid (200:3, v/v) in one dimension, (2) benzene- glacial acetic...
Identification of plant mitochondrial proteins: A procedure linking two-dimensional gel electrophoresis to protein sequencing from PVDF membranes using a FastBlot cycle
Bryan Dunbar; Thomas E. Elthon; John C. Osterman; Beth A. Whitaker; S. Brian Wilson
Identification of the 329 spots visible in 2D gels of plant mitochondrial proteins is a challenge. This paper describes a\\u000a 2D mini-gel protocol involving free-radical scavengers and purified reagents to make it compatible with protein sequencing,\\u000a and evaluates its performance. The paper also describes a �FastBlot� sequencing cycle with the cycle time for protein sequencing\\u000a from PVDF membranes reduced to
Biodegradation of cellulose acetate by Neisseria sicca.
Sakai, K; Yamauchi, T; Nakasu, F; Ohe, T
Bacteria capable of assimilating cellulose acetate, strains SB and SC, were isolated from soil on a medium containing cellulose acetate as a carbon source, and identified as Neisseria sicca. Both strains degraded cellulose acetate membrane filters (degree of substitution, DS, mixture of 2.8 and 2.0) and textiles (DS, 2.34) in a medium containing cellulose acetate (DS, 2.34) or its oligomer, but were not able to degrade these materials in a medium containing cellobiose octaacetate. Biodegradation of cellulose acetate (DS, 1.81 and 2.34) on the basis of biochemical oxygen demand reached 51 and 40% in the culture of N. sicca SB and 60 and 45% in the culture of N. sicca SC within 20 days. A decrease in the acetyl content of degraded cellulose acetate films and powder was confirmed by infrared and nuclear magnetic resonance analyses. After 10-day cultivation of N. sicca SB and SC, the number-average molecular weight of residual cellulose acetate decreased by 9 and 5%, respectively. Activities of enzymes that released acetic acid and produced reducing sugars from cellulose acetate were mainly present in the culture supernatant. Reactivity of enzymes for cellulose acetate (DS, 1.81) was higher than that for cellulose acetate (DS, 2.34). PMID:8987659
NASA Technical Reports Server (NTRS)
Todd, P.
Materials and procedures for microgravity electrophoresis of living human embryonic kidney cells were evaluated, ground support in the form of analytical cell electrophoresis and flow cytometry was provided and cells returned from space flight were analyzed. Preflight culture media, electrophoresis buffer, fraction collection media, temperature profiles, and urokinase assay procedures were tested prior to flight. Electrophoretic mobility distributions of aliquots of the cell population to be fractionated in flight were obtained. The protocol established and utilized is given.
Automatic multiple applicator electrophoresis
NASA Technical Reports Server (NTRS)
Grunbaum, B. W.
Easy-to-use, economical device permits electrophoresis on all known supporting media. System includes automatic multiple-sample applicator, sample holder, and electrophoresis apparatus. System has potential applicability to fields of taxonomy, immunology, and genetics. Apparatus is also used for electrofocusing.
Electrophoresis of biological materials
NASA Technical Reports Server (NTRS)
The selection of biological products was studied for electrophoresis in space. Free flow electrophoresis, isoelectric focusing, and isotachophoresis are described. The candidates discussed include: immunoglobulins and gamma globulins; isolated islet of langerhans from pancreas; bone marrow; tumor cells; kidney cells, cryoprecipitate; and column separated cultures.
Effect of phorbol myristate acetate on secretion of parathyroid hormone
Morrissey, J.J. (Washington Univ. School of Medicine, St. Louis, MO (USA))
The influence of phorbol myristate acetate (PMA), an activator of protein kinase c, on the secretion of parathyroid hormone from collagenase-dispersed bovine parathyroid cells was tested. The cells were incubated at low or high concentrations of calcium in the medium, and the hormone secreted into the medium was measured by a radioimmunoassay that recognizes both intact and C-terminal fragments of hormone. A stimulatory effect of PMA at high calcium, seen at PMA concentrations as low as 1.6 nM, did not occur with a biologically inactive 4{alpha}-isomer of phorbol ester, and was independent of changes in cellular adenosine 3{prime},5{prime}-cyclic monophosphate levels. Examination of {sup 32}P-labeled phosphoproteins by two-dimensional gel electrophoresis revealed acidic proteins of {approximately}20,000 and 100,000 Da that were phosphorylated at low and high calcium + 1.6 {mu}M PMA but not at high calcium alone. The protein kinase c activity associated with the membrane fraction of parathyroid cells significantly decreased 40% when the cells were incubated at high vs. low calcium. The data suggest that calcium may regulate parathyroid hormone secretion through changes in protein kinase c activity of the membrane fraction of the cell and protein phosphorylation.
Preparative electrophoresis experiment design
NASA Technical Reports Server (NTRS)
Thiehler, A.
A multifaceted study supporting the NASA programs to develop a space electrophoresis capability has been conducted. The study involved principally the technique of continuous free electrophoresis. It comprised a critical review of the art, study of new techniques for enhancing resolution and stability, and construction and initial testing of a high resolution cell. The effort resulted in a significant advance in free electrophoresis technique. It has provided also a much improved base for developments exploiting the added advantages of a zero-gravity environment.
Measuring Genetic Variation in Zebra Mussels Using Acetate Electrophoresis
NSDL National Science Digital Library
Corey A Goldman (University of Toronto; )
This resource is a mini-workshop for instructing a laboratory exercise in genetics and evolutionary biology. Students learn concepts of genetic variability and equilibria in natural populations. This resource can be used to organize laboratory exercises for classes in genetics and evolutionary biology.
Using capillary electrophoresis for failure analysis
Kelly, R.G.; Scully, H.S.; Stoner, G.E. (Univ. of Virginia, Charlottesville, VA (United States). Center for Electrochemical Science and Engineering)
Capillary electrophoresis (CE), an advanced solution analysis technique, can be used for failure analysis of corroded components. It has high sensitivity (concentrations as low as parts-per-trillion) and can detect quantitatively a large number of ionic species. CE determined the vapor-phase attack by organic acids, mainly acetic acid, on an electrical equipment enclosure. These acids most likely originated from the seasoning of the oak pallets used to transport the manufactured items, accumulating inside the shrink-wrap film used to bind packages to the pallet.
Capillary electrophoresis-mass spectrometry of carbohydrates
Zaia, Joseph
The development of methods for capillary electrophoresis (CE) with on-line mass spectrometric detection (CE/MS) is driven by the need for accurate, robust and sensitive glycomics analysis for basic biomedicine, biomarker discovery, and analysis of recombinant protein therapeutics. One important capability is to profile glycan mixtures with respect to the patterns of substituents including sialic acids, acetate, sulfate, phosphate, and other groups. There is additional need for an MS-compatible separation system capable of resolving carbohydrate isomers. This review summarizes applications of CS/MS to analysis of carbohydrates, glycoproteins and glycopeptides that have appeared since 2008. Readers are referred to recent comprehensive reviews covering earlier publications. PMID:23386333
Recent advances in preparative electrophoresis
NASA Technical Reports Server (NTRS)
Mosher, Richard A.; Thormann, Wolfgang; Egen, Ned B.; Couasnon, Pascal; Sammons, David W.
Various approaches for preparative electrophoresis, and three new instruments for preparative electrophoresis are discussed. Consideration is given to isoelectric focusing, isotachophoresis, and zone electrophoresis, three gel-based electrophoresis methods. The design, functions, and performance of the Elphor VaP 21 device of Hannig (1982), the shear-stabilized BIOSTREAM separator of Thompson (1983), and the recycling isoelectric focusing device are described.
Capillary Electrophoresis of Bacterial (Lipo)Polysaccharides
Nicola Volpi; Francesca Maccari
\\u000a Lipopolysaccharides (LPSs) are major components of the outer �membrane of gram-negative bacteria, and, along with some acidic\\u000a polysaccharides, are important macromolecules belonging to bacteria. The recent emergence of modern �analytical tools for\\u000a their study has produced a virtual explosion in the field of glycomics. Capillary electrophoresis (CE), due to its high resolving\\u000a power and sensitivity, has been useful in the
Downstream processing of acetate fermentation broths by nanofiltration
In Soo Han; Munir Cheryan
Acetate can be separated from fermentation broths and partially purified by nanofiltration (NF). Membrane performance was\\u000a a function of pressure, pH, concentration of acetate, temperature, and the presence of other media components. With Nitto-Denko�s\\u000a NTR729 membrane, average acetate rejection was 60%, glucose rejection was 99%, and flux was 15 L\\/m2\\/h at 200 psig, 30�C, pH 5.6, and 20 g\\/L acetic
NSDL National Science Digital Library
Janice Stephens
In this experiment related to plant biotechnology, learners discover how to prepare and load an electrophoresis gel. They will then run the gels in an electrophoresis system to separate several dyes that are of different molecular sizes and carry different charges. This technique is fundamental to many of the procedures used in biotechnology. This lesson guide includes background information for the educator, safety precautions, and questions with answers for learners. For safety reasons, adult supervision is recommended. Modifications for use with younger learners are described in a related PDF (see related resource).
Fraction collector for electrophoresis
NASA Technical Reports Server (NTRS)
Bier, M.
Rotating-tube electrophoresis apparatus employs rotating jet of eluting buffer to reduce effects of convection during separation. Designed for separation of microorganisms and biological species, system combines gravity/gradient compensating of lumen with buffer flush at fraction outlet to increase separation efficiency.
During this year we performed two major projects: I. We developed a detailed theoretical model which complements our experiments on surface DNA electrophoresis. We found that it was possible to enhance the separation of DNA chains by imposing a chemical nanoscale pattern on the surface. This approach utilized the surface interaction effect of the DNA chains with the substrate and is a refinement to our previous method in which DNA chains were separated on homogeneous flat surfaces. By introducing the nano-patterns on the surface, the conformational changes of DNA chains of different lengths can be amplified, which results in the different friction strengths with the substrate surface. Our results also show that, when compared to the DNA electrophoresis performed on homogeneous flat surfaces, nanopatterned surfaces offer a larger window in choosing different surface interactions to achieve separation. II. In collaboration with a large international manufacturer of skin care products we also embarked on a project involving photo toxicity of titanium dioxide nanoparticles, which are a key ingredient in sunscreen and cosmetic lotions. The results clearly implicated the nanoparticles in catalyzing damage to chromosomal DNA. We then used this knowledge to develop a polymer/anti-oxidant coating which prevented the photocatalytic reaction on DNA while still retaining the UV absorptive properties of the nanoparticles. The standard gel electrophoresis was not sufficient in determining the extent of the DNA damage. The conclusions of this study were based predominantly on analysis obtained with the surface electrophoresis method.
Automatic multiple-sample applicator and electrophoresis apparatus
NASA Technical Reports Server (NTRS)
Grunbaum, B. W. (inventor)
An apparatus for performing electrophoresis and a multiple-sample applicator is described. Electrophoresis is a physical process in which electrically charged molecules and colloidal particles, upon the application of a dc current, migrate along a gel or a membrane that is wetted with an electrolyte. A multiple-sample applicator is provided which coacts with a novel tank cover to permit an operator either to depress a single button, thus causing multiple samples to be deposited on the gel or on the membrane simultaneously, or to depress one or more sample applicators separately by means of a separate button for each applicator.
Pallidol hexa�acetate ethyl acetate monosolvate
Mao, Qinyong; Taylor, Dennis K.; Ng, Seik Weng; Tiekink, Edward R. T.
The entire mol�ecule of pallidol hexa�acetate {systematic name: (�)-(4bR,5R,9bR,10R)-5,10-bis�[4-(acet�yloxy)phen�yl]-4b,5,9b,10-tetra�hydro�indeno�[2,1-a]indene-1,3,6,8-tetrayl tetra�acetate} is completed by the application of twofold rotational symmetry in the title ethyl acetate solvate, C40H34O12�C4H8O2. The ethyl acetate mol�ecule was highly disordered and was treated with the SQUEEZE routine [Spek (2009 ?). Acta Cryst. D65, 148�155]; the crystallographic data take into account the presence of the solvent. In pallidol hexa�acetate, the dihedral angle between the fused five-membered rings (r.m.s. deviation = 0.100?�) is 54.73?(6)�, indicating a significant fold in the mol�ecule. Significant twists between residues are also evident as seen in the dihedral angle of 80.70?(5)� between the five-membered ring and the pendent benzene ring to which it is attached. Similarly, the acetate residues are twisted with respect to the benzene ring to which they are attached [C�O(carb�oxy)�C�C torsion angles = ?70.24?(14), ?114.43?(10) and ?72.54?(13)�]. In the crystal, a three-dimensional architecture is sustained by C�H?O inter�actions which encompass channels in which the disordered ethyl acetate mol�ecules reside. PMID:24046702
Happy bicentennial, electrophoresis!
Righetti, Pier Giorgio
A short survey of electrophoresis and a celebration of its bicentennial, with some remarkable mementos and a list of books that shaped the field. Where one also learns of a secret production plant with a huge-scale electrophoretic apparatus for skimming of latex from Hevea brasiliensis and keeping the wheels of the Ally Army running during World War II. And of cyber (mammoth) 2D gels of 1.5 x 1 m in size accommodating >12,000 spots. PMID:19938305
Electrophoresis experiments in microgravity
NASA Technical Reports Server (NTRS)
Snyder, Robert S.; Rhodes, Percy H.
The use of the microgravity environment to separate and purify biological cells and proteins has been a major activity since the beginning of the NASA Microgravity Science and Applications program. Purified populations of cells are needed for research, transplantation and analysis of specific cell constituents. Protein purification is a necessary step in research areas such as genetic engineering where the new protein has to be separated from the variety of other proteins synthesized from the microorganism. Sufficient data are available from the results of past electrophoresis experiments in space to show that these experiments were designed with incomplete knowledge of the fluid dynamics of the process including electrohydrodynamics. However, electrophoresis is still an important separation tool in the laboratory and thermal convection does limit its performance. Thus, there is a justification for electrophoresis but the emphasis of future space experiments must be directed toward basic research with model experiments to understand the microgravity environment and fluid analysis to test the basic principles of the process.
Preparative electrophoresis for space
NASA Technical Reports Server (NTRS)
Rhodes, Percy H.; Snyder, Robert S.
A premise of continuous flow electrophoresis is that removal of buoyance-induced thermal convection caused by axial and lateral temperature gradients results in ideal performance of these instruments in space. Although these gravity dependent phenomena disturb the rectilinear flow in the separation chamber when high voltage gradients or thick chamber are used, distortion of the injected sample stream due to electrodynamic effects cause major broadening of the separated bands. The electrophoresis separation process is simple, however flow local to the sample filament produced by the applied electric field were not considered. These electrohydrodynamic flows distort the sample stream and limit the separation. Also, electroosmosis and viscous flow combine to further distort the process. A moving wall concept is being proposed for space which will eliminate and control the disturbances. The moving wall entrains the fluid to move as a rigid body and produces a constant residence time for all samples distributed across the chamber thickness. The moving wall electrophoresis chamber can only be operated in space because there is no viscous flow in the chamber to stabilize against thermal convection.
Preparative electrophoresis for space
NASA Technical Reports Server (NTRS)
Rhodes, Percy H.; Snyder, Robert S.
A premise of continuous flow electrophoresis is that removal of buoyancy-induced thermal convection caused by axial and lateral temperature gradients results in ideal performance of these instruments in space. Although these gravity dependent phenomena disturb the rectilinear flow in the separation chamber when high voltage gradients or thick chambers are used, distortion of the injected sample stream due to electrohydrodynamic effects cause major broadening of the separated bands. The electrophoresis separation process is simple, however flow local to the sample filament produced by the applied electric field have not been considered. These electrohydrodynamic flows distort the sample stream and limit the separation. Also, electroosmosis and viscous flow combine to further distort the process. A moving wall concept is being proposed for space which will eliminate and control the disturbances. The moving wall entrains the fluid to move as a rigid body and produces a constant residence time for all samples distributed across the chamber thickness. The moving wall electrophoresis chamber can only be operated in space because there is no viscous flow in the chamber to stabilize against thermal convection.
Detection of Polymorphisms of Human DNA by Gel Electrophoresis as Single-Strand Conformation Polymorphisms
Masato Orita; Hiroyuki Iwahana; Hiroshi Kanazawa; Kenshi Hayashi; Takao Sekiya
We developed mobility shift analysis of single-stranded DNAs on neutral polyacrylamide gel electrophoresis to detect DNA polymorphisms. This method follows digestion of genomic DNA with restriction endonucleases, denaturation in alkaline solution, and electrophoresis on a neutral polyacrylamide gel. After transfer to a nylon membrane, the mobility shift due to a nucleotide substitution of a single-stranded DNA fragment could be detected
Tustin, Gerald Charles (Kingsport, TN); Zoeller, Joseph Robert (Kingsport, TN); Depew, Leslie Sharon (Kingsport, TN)
This invention pertains to the preparation of vinyl acetate by contacting a mixture of hydrogen and ketene with a heterogeneous catalyst containing a transition metal to produce acetaldehyde, which is then reacted with ketene in the presence of an acid catalyst to produce vinyl acetate.
Tustin, G.C.; Zoeller, J.R.; Depew, L.S.
This invention pertains to the preparation of vinyl acetate by contacting a mixture of hydrogen and ketene with a heterogeneous catalyst containing a transition metal to produce acetaldehyde, which is then reacted with ketene in the presence of an acid catalyst to produce vinyl acetate.
Association for Biology Laboratory Education (ABLE) ~ http://www.zoo.utoronto.ca/able Demystifying Hardy-Weinberg: Using Cellulose Acetate
Demystifying Hardy-Weinberg: Using Cellulose Acetate Electrophoresis of the Lap Locus to Study Population From: Peroni, P. A. and D. E. McCauley. 1999. Demystifying Hardy-Weinberg: Using cellulose acetate................................................................114 Appendix B: Calculation of Allele and Genotype Frequencies and Hardy-Weinberg Review
Multiplexed capillary electrophoresis system
Yeung, Edward S. (Ames, IA); Chang, Huan-Tsang (Silver Spring, MD); Fung, Eliza N. (Ames, IA); Li, Qingbo (Ames, IA); Lu, Xiandan (Ames, IA)
The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification ("base calling") is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations.
Multiplexed capillary electrophoresis system
Yeung, E.S.; Li, Q.; Lu, X.
The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification (``base calling``) is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations. 19 figs.
Multiplexed capillary electrophoresis system
Yeung, Edward S. (Ames, IA); Li, Qingbo (Ames, IA); Lu, Xiandan (Ames, IA)
The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification ("base calling") is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations.
Multiplexed capillary electrophoresis system
Yeung, E.S.; Chang, H.T.; Fung, E.N.; Li, Q.; Lu, X.
The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification (``base calling``) is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations. 19 figs.
((35)S)sulfate incorporation into glomerular basement membrane glycosaminoglycans is decreased in experimental diabetes
Cohen, M.P.; Surma, M.L.
Isolated rat renal glomeruli incorporate radioactive sulfate into glycosaminoglycans, which are integral components of the glomerular basement membrane. Cellulose acetate electrophoresis and specific enzymatic sensitivities of glycosaminoglycans prepared after pronase digestion of purified glomerular basement membrane indicate the presence of heparan sulfate. We examined the effect of experimental diabetes on the incorporation of ((35)S)-sulfate into glycosaminoglycans deposited into newly synthesized glomerular basement membrane in vitro. Basement membranes were purified from glomeruli isolated from normal and streptozotocin-diabetic rats after incubation for 2 hr with radiolabeled sulfate and then were subjected to pronase digestion for isolation of the glycosaminoglycans. ((35)S) incorporation into basement membrane glycosaminoglycans was significantly decreased in glomeruli from diabetic animals. The addition of insulin (100 micron U/ml) in vitro did not affect ((35)S) incorporation into glycosaminoglycans of the glomerular basement membranes in normal or diabetic glomeruli. High glucose concentration (5 vs. 20 mM) was without effect in short-term incubations of glomeruli from normal animals. The results indicate that experimental diabetes influences ((35)S) sulfate incorporation into glomerular basement membrane glycosaminoglycans and suggest that decreased heparan sulfate production and/or sulfation may contribute to the increased permeability of the glomerular basement membrane in diabetes.
Vesicles protect activated acetic acid.
Todd, Zoe R; House, Christopher H
Abstract Methyl thioacetate, or activated acetic acid, has been proposed to be central to the origin of life and an important energy currency molecule in early cellular evolution. We have investigated the hydrolysis of methyl thioacetate under various conditions. Its uncatalyzed rate of hydrolysis is about 3 orders of magnitude faster (K=0.00663 s(-1); 100�C, pH 7.5, concentration=0.33 mM) than published rates for its catalyzed production, making it unlikely to accumulate under prebiotic conditions. However, our experiments showed that methyl thioacetate was protected from hydrolysis when inside its own hydrophobic droplets. Further, we found that methyl thioacetate protection from hydrolysis was also possible in droplets of hexane and in the membranes of nonanoic acid vesicles. Thus, the hydrophobic regions of prebiotic vesicles and early cell membranes could have offered a refuge for this energetic molecule, increasing its lifetime in close proximity to the reactions for which it would be needed. This model of early energy storage evokes an additional critical function for the earliest cell membranes. PMID:25280019
Static continuous electrophoresis device
NASA Technical Reports Server (NTRS)
Rhodes, P. H. (inventor)
An apparatus is disclosed for carrying out a moving wall type electrophoresis process for separation of cellular particles. The apparatus includes a water-tight housing containing an electrolytic buffer solution. A separation chamber in the housing is defined by spaced opposed moving walls and spaced opposed side walls. Substrate assemblies, which support the moving wall include vacuum ports for positively sealing the moving walls against the substrate walls. Several suction conduits communicate with the suction ports and are arranged in the form of valleys in a grid plate. The raised land portion of the grid plat supports the substrate walls against deformation inwardly under suction. A cooling chamber is carried on the back side of plate. The apparatus also has tensioner means including roller and adjustment screws for maintaining the belts in position and a drive arrangement including an electric motor with a gear affixed to its output shaft. Electrode assemblies are disposed to provide the required electric field.
Electrophoresis experiment for space
NASA Technical Reports Server (NTRS)
Vanderhoff, J. W.; Micale, F. J.
The Apollo 16 electrophoresis experiment was analyzed, demonstrating that the separation of the two different-size monodisperse latexes did indeed take place, but that the separation was obscured by the pronounced electroosmotic flow of the liquid medium. The results of this experiment, however, were dramatic since it is impossible to carry out a similar separation on earth. It can be stated unequivocally from this experiment that any electrophoretic separation will be enhanced under microgravity conditions. The only question is the degree of this enhancement, which can be expected to vary from one experimental technique to another. The low-electroosmotic-mobility coating (Z6040-MC) developed under this program was found to be suitable for a free-fluid electrophoretic separation such as the experiment designed for the ASTP flight. The problem with this coating, however, is that its permanency is limited because of the slow desorption of the methylcellulose from the coated surface.
Electrophoresis demonstration on Apollo 16
NASA Technical Reports Server (NTRS)
Snyder, R. S.
Free fluid electrophoresis, a process used to separate particulate species according to surface charge, size, or shape was suggested as a promising technique to utilize the near zero gravity condition of space. Fluid electrophoresis on earth is disturbed by gravity-induced thermal convection and sedimentation. An apparatus was developed to demonstrate the principle and possible problems of electrophoresis on Apollo 14 and the separation boundary between red and blue dye was photographed in space. The basic operating elements of the Apollo 14 unit were used for a second flight demonstration on Apollo 16. Polystyrene latex particles of two different sizes were used to simulate the electrophoresis of large biological particles. The particle bands in space were extremely stable compared to ground operation because convection in the fluid was negligible. Electrophoresis of the polystyrene latex particle groups according to size was accomplished although electro-osmosis in the flight apparatus prevented the clear separation of two particle bands.
Kidney cell electrophoresis, continuing task
NASA Technical Reports Server (NTRS)
Todd, P. W.
Materials and procedures for microgravity electrophoresis of living human embryonic kidney cells were evaluated to provide ground support in the form of analytical cell electrophoresis and flow cytometry. Preflight culture media, electrophoresis buffer, fraction collection media, temperature profiles, and urokinase assay procedures were tested prior to flight. Electrophoretic mobility distributions of aliquots of the cell population to be fractionated in flight were obtained. Cells were prepared in suspension prior to flight in electrophoresis buffer and 10% calf serum. Electrophoretic separation proceeded in electrophoresis buffer without serum in the Continuous Flow Electrophoretic Separator, and fractions were collected into sample bags containing culture medium and concentrated serum. Fractions that yielded enough progeny cells were analyzed for morphology and electrophoretic mobility distributions. It is noted that the lowest mobility fraction studied produced higher mobility progeny while the other fractions produced progeny cells with mobilities related to the fractions from which they were collected.
Binary Oscillatory Crossflow Electrophoresis
NASA Technical Reports Server (NTRS)
Molloy, Richard F.; Gallagher, Christopher T.; Leighton, David T., Jr.
Electrophoresis has long been recognized as an effective analytic technique for the separation of proteins and other charged species, however attempts at scaling up to accommodate commercial volumes have met with limited success. In this report we describe a novel electrophoretic separation technique - Binary Oscillatory Crossflow Electrophoresis (BOCE). Numerical simulations indicate that the technique has the potential for preparative scale throughputs with high resolution, while simultaneously avoiding many problems common to conventional electrophoresis. The technique utilizes the interaction of an oscillatory electric field and a transverse oscillatory shear flow to create an active binary filter for the separation of charged protein species. An oscillatory electric field is applied across the narrow gap of a rectangular channel inducing a periodic motion of charged protein species. The amplitude of this motion depends on the dimensionless electrophoretic mobility, alpha = E(sub o)mu/(omega)d, where E(sub o) is the amplitude of the electric field oscillations, mu is the dimensional mobility, omega is the angular frequency of oscillation and d is the channel gap width. An oscillatory shear flow is induced along the length of the channel resulting in the separation of species with different mobilities. We present a model that predicts the oscillatory behavior of charged species and allows estimation of both the magnitude of the induced convective velocity and the effective diffusivity as a function of a in infinitely long channels. Numerical results indicate that in addition to the mobility dependence, the steady state behavior of solute species may be strongly affected by oscillating fluid into and out of the active electric field region at the ends of the cell. The effect is most pronounced using time dependent shear flows of the same frequency (cos((omega)t)) flow mode) as the electric field oscillations. Under such conditions, experiments indicate that solute is drawn into the cell from reservoirs at both ends of the cell leading to a large mass build up. As a consequence, any initially induced mass flux will vanish after short times. This effect was not captured by the infinite channel model and hence numerical and experimental results deviated significantly. The revised model including finite cell lengths and reservoir volumes allowed quantitative predictions of the time history of the concentration profile throughout the system. This latter model accurately describes the fluxes observed for both oscillatory flow modes in experiments using single protein species. Based on the results obtained from research funded under NASA grant NAG-8-1080.S, we conclude that binary separations are not possible using purely oscillatory flow modes because of end effects associated with the cos((omega)t) mode. Our research shows, however, that a combination of cos(2(omega)t) and steady flow should lead to efficient separation free of end effects. This possibility is currently under investigation.
Copolymers For Capillary Gel Electrophoresis
Liu, Changsheng (State College, PA); Li, Qingbo (State College, PA)
This invention relates to an electrophoresis separation medium having a gel matrix of at least one random, linear copolymer comprising a primary comonomer and at least one secondary comonomer, wherein the comonomers are randomly distributed along the copolymer chain. The primary comonomer is an acrylamide or an acrylamide derivative that provides the primary physical, chemical, and sieving properties of the gel matrix. The at least one secondary comonomer imparts an inherent physical, chemical, or sieving property to the copolymer chain. The primary and secondary comonomers are present in a ratio sufficient to induce desired properties that optimize electrophoresis performance. The invention also relates to a method of separating a mixture of biological molecules using this gel matrix, a method of preparing the novel electrophoresis separation medium, and a capillary tube filled with the electrophoresis separation medium.
DNA typing by capillary electrophoresis
Zhang, N.
Capillary electrophoresis is becoming more and more important in nucleic acid analysis including DNA sequencing, typing and disease gene measurements. This work summarized the background of DNA typing. The recent development of capillary electrophoresis was also discussed. The second part of the thesis showed the principle of DNA typing based on using the allelic ladder as the absolute standard ladder in capillary electrophoresis system. Future work will be focused on demonstrating DNA typing on multiplex loci and examples of disease diagnosis in the on-line format of PCR-CE. Also capillary array electrophoresis system should allow high throughput, fast speed DNA typing. Only the introduction and conclusions for this report are available here. A reprint was removed for separate processing.
Fragrance material review on ?-methylbenzyl acetate.
McGinty, D; Letizia, C S; Api, A M
A toxicologic and dermatologic review of ?-methylbenzyl acetate when used as a fragrance ingredient is presented. ?-Methylbenzyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for ?-methylbenzyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, and repeated dose data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22406576
Fragrance material review on piperonyl acetate.
McGinty, D; Letizia, C S; Api, A M
A toxicologic and dermatologic review of piperonyl acetate when used as a fragrance ingredient is presented. Piperonyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for piperonyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, toxicokinetics, and genotoxicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22445840
Fragrance material review on benzyl acetate.
McGinty, D; Vitale, D; Letizia, C S; Api, A M
A toxicologic and dermatologic review of benzyl acetate when used as a fragrance ingredient is presented. Benzyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for benzyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, phototoxicity, toxicokinetics, repeated dose, reproductive toxicity, genotoxicity, or carcinogenicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Refer Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22387848
Fragrance material review on 2-phenylpropyl acetate.
McGinty, D; Letizia, C S; Api, A M
A toxicologic and dermatologic review of 2-phenylpropyl acetate when used as a fragrance ingredient is presented. 2-Phenylpropyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2-phenylpropyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, and skin sensitization data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22421639
Antibody enhancement of free-flow electrophoresis
NASA Technical Reports Server (NTRS)
Cohly, H. H. P.; Morrison, Dennis R.; Atassi, M. Zouhair
Specific T cell clones and antibodies (ABs) were developed to study the efficiency of purifying closely associated T cells using Continuous Flow Electrophoresis System. Enhanced separation is accomplished by tagging cells first with ABs directed against the antigenic determinants on the cell surface and then with ABs against the Fc portion of the first AB. This second AB protrudes sufficiently beyond the cell membrane and glycocalyx to become the major overall cell surface potential determinant and thus causes a reduction of electrophoretic mobility. This project was divided into three phases. Phase one included development of specific T cell clones and separation of these specific clones. Phase two extends these principles to the separation of T cells from spleen cells and immunized lymph node cells. Phase three applies this double antibody technique to the separation of T cytotoxic cells from bone marrow.
Overview on mechanisms of acetic acid resistance in acetic acid bacteria.
Wang, Bin; Shao, Yanchun; Chen, Fusheng
Acetic acid bacteria (AAB) are a group of gram-negative or gram-variable bacteria which possess an obligate aerobic property with oxygen as the terminal electron acceptor, meanwhile transform ethanol and sugar to corresponding aldehydes, ketones and organic acids. Since the first genus Acetobacter of AAB was established in 1898, 16 AAB genera have been recorded so far. As the main producer of a world-wide condiment, vinegar, AAB have evolved an elegant adaptive system that enables them to survive and produce a high concentration of acetic acid. Some researches and reviews focused on mechanisms of acid resistance in enteric bacteria and made the mechanisms thoroughly understood, while a few investigations did in AAB. As the related technologies with proteome, transcriptome and genome were rapidly developed and applied to AAB research, some plausible mechanisms conferring acetic acid resistance in some AAB strains have been published. In this review, the related mechanisms of AAB against acetic acid with acetic acid assimilation, transportation systems, cell morphology and membrane compositions, adaptation response, and fermentation conditions will be described. Finally, a framework for future research for anti-acid AAB will be provided. PMID:25575804
Ulipristal acetate: in uterine fibroids.
Croxtall, Jamie D
Ulipristal acetate, a selective progesterone-receptor modulator, inhibits the proliferation and induces apoptosis of leiomyoma cells in vitro. It also modulates the expression of vascular endothelial growth factors and hormone receptors and modulates extracellular matrix breakdown in leiomyoma cells but not in myometrial cells. In two randomized, double-blind, multinational phase III trials of 13 weeks' duration in women aged 18-50 years with uterine fibroids, a once-daily regimen of oral ulipristal acetate 5 mg/day controlled excessive uterine bleeding (primary endpoint) in ?90% of patients. Ulipristal acetate 5 mg/day was more effective than placebo and was shown to be noninferior to intramuscular leuprolide acetate 3.75 mg once monthly in controlling uterine bleeding. Uterine bleeding was rapidly controlled by ulipristal acetate. Approximately half of recipients of ulipristal acetate 5 mg/day became amenorrhoeic within the first 10 days of treatment. Furthermore, uterine bleeding was controlled significantly more rapidly for recipients of ulipristal acetate than recipients of leuprolide acetate. A significantly greater median reduction from baseline in total fibroid volume was observed for recipients of ulipristal acetate 5 mg once daily than recipients of placebo following 13 weeks' treatment (coprimary endpoint). For patients who did not undergo surgery, the volume reduction was maintained for at least 6 months after discontinuing treatment. Ulipristal acetate was generally well tolerated in women with uterine fibroids. The incidence of hot flush occurred with a significantly lower frequency for recipients of ulipristal acetate than for recipients of leuprolide acetate. PMID:22568731
Comerford, Sarah A; Huang, Zhiguang; Du, Xinlin; Wang, Yun; Cai, Ling; Witkiewicz, Agnes K; Walters, Holly; Tantawy, Mohammed N; Fu, Allie; Manning, H Charles; Horton, Jay D; Hammer, Robert E; McKnight, Steven L; Tu, Benjamin P
Acetyl-CoA represents a central node of carbon metabolism that plays a key role in bioenergetics, cell proliferation, and the regulation of gene expression. Highly glycolytic or hypoxic tumors must produce sufficient quantities of this metabolite to support cell growth and survival under nutrient-limiting conditions. Here, we show that the nucleocytosolic acetyl-CoA synthetase enzyme, ACSS2, supplies a key source of acetyl-CoA for tumors by capturing acetate as a carbon source. Despite exhibiting no gross deficits in growth or development, adult mice lacking ACSS2 exhibit a significant reduction in tumor burden in two different models of hepatocellular carcinoma. ACSS2 is expressed in a large proportion of human tumors, and its activity is responsible for�the majority of cellular acetate uptake into both lipids and histones. These observations may qualify ACSS2 as a targetable metabolic vulnerability of a wide spectrum of tumors. PMID:25525877
Automated zone electrophoresis--experiments and new concepts.
Fosslien, E
I have investigated various modalities of automation of zone electrophoresis. One system has already been previously described (U.S. Pat. No. 3,896,021). Other systems investigated can be divided into batch systems and one random-access system; the former involve separation on cellulose acetate that is supported on 0.127 mm thick polyester (Mylar) film in the form of tape, cards, or discs. Systems in which the separation is in a direction transverse to the long axis of the tape use a typical tape width of 7.5 cm; systems in which separation is longitudinal make use of supports of various widths, depending upon the assay rate desired. Concepts were also developed for a random-access systems for automated electrophoresis, which requires no start-up time. Small Lucite cassettes are used, one for each sample. Each cassette has one surface of either cellulose acetate or any of several gels used for electrophoretic separation. There are further small wells for sample and calibrator. The loaded cassette is inserted into an input queue that allows serial processing. The cassettes move sequentially through prewetting (if needed), sample application, electrophoretic separation, staining, and scanning. This system should also be suitable for automated isoelectric focusing. PMID:872406
Separation and determination of phospholipids in plant seeds by nonaqueous capillary electrophoresis.
Guo, Bao-Yuan; Wen, Bei; Shan, Xiao-Quan; Zhang, Shu-Zheng; Lin, Jin-Ming
A method has been developed for the separation and determination of phospholipids by nonaqueous capillary electrophoresis in a separation medium of acetonitrile-2-proponol (3:2, v/v), 0.3% acetic acid and 60 mM ammonium acetate. To optimize the separation conditions, the composition of separation medium including alcohols, acetic acid, n-hexane and ammonium acetate was studied. The solvation interaction and ion-dipole interaction were also investigated. The contents of phospholipids in soybean, sunflower, peanut, apricot kernel, filbert and walnut were determined by the recommended method. The results obtained by the nonaqueous capillary electrophoreses were in good agreement with those determined by micellar electrokinetic chromatography. PMID:15941057
Introduction to Agarose Gel Electrophoresis
NSDL National Science Digital Library
CLIMB: Cornell's Learning Initiative in Medicine and Bioengineering
In this module, developed as part of Cornell's Learning Initiative in Medicine and Bioengineering (CLIMB), students are introduced to the concepts of gel electrophoresis without requiring all the equipment needed to run a full gel electrophoresis experiment. The goal is to have students understand how gels are made for DNA separation and how altering the composition can affect the experimental parameters. This module contains a teacher's guide, classroom activity, and suggestions for extended activities. This lab is a precursor to Cornell�s Institute for Biology Teachers lab�s entitled DNA Profiling � Paternity Testing, which is linked within the teacher's guide. CLIMB is part of the NSF GK-12 program.
Capillary electrophoresis of inorganic anions.
Kaniansky, D; Mas�r, M; Mar�k, J; Bodor, R
This review deals with the separation mechanisms applied to the separation of inorganic anions by capillary electrophoresis (CE) techniques. It covers various CE techniques that are suitable for the separation and/or determination of inorganic anions in various matrices, including capillary zone electrophoresis, micellar electrokinetic chromatography, electrochromatography and capillary isotachophoresis. Detection and sample preparation techniques used in CE separations are also reviewed. An extensive part of this review deals with applications of CE techniques in various fields (environmental, food and plant materials, biological and biomedical, technical materials and industrial processes). Attention is paid to speciations of anions of arsenic, selenium, chromium, phosphorus, sulfur and halogen elements by CE. PMID:10189691
Acetate oxidation by syntrophic association between Geobacter sulfurreducens and a hydrogen-utilizing exoelectrogen
Kimura, Zen-ichiro; Okabe, Satoshi
Anodic microbial communities in acetate-fed microbial fuel cells (MFCs) were analyzed using stable-isotope probing of 16S rRNA genes followed by denaturing gradient gel electrophoresis. The results revealed that Geobacter sulfurreducens and Hydrogenophaga sp. predominated in the anodic biofilm. Although the predominance of Geobacter sp. as acetoclastic exoelectrogens in acetate-fed MFC systems has been often reported, the ecophysiological role of Hydrogenophaga sp. is unknown. Therefore, we isolated and characterized a bacterium closely related to Hydrogenophaga sp. (designated strain AR20). The newly isolated strain AR20 could use molecular hydrogen (H2), but not acetate, with carbon electrode as the electron acceptor, indicating that the strain AR20 was a hydrogenotrophic exoelectrogen. This evidence raises a hypothesis that acetate was oxidized by G. sulfurreducens in syntrophic cooperation with the strain AR20 as a hydrogen-consuming partner in the acetate-fed MFC. To prove this hypothesis, G. sulfurreducens strain PCA was cocultivated with the strain AR20 in the acetate-fed MFC without any dissolved electron acceptors. In the coculture MFC of G. sulfurreducens and strain AR20, current generation and acetate degradation were the highest, and the growth of strain AR20 was observed. No current generation, acetate degradation and cell growth occurred in the strain AR20 pure culture MFC. These results show for the first time that G. sulfurreducens can oxidize acetate in syntrophic cooperation with the isolated Hydrogenophaga sp. strain AR20, with electrode as the electron acceptor. PMID:23486252
Acetate Kinase Isozymes Confer Robustness in Acetate Metabolism
Chan, Siu Hung Joshua; N�rregaard, Lasse; Solem, Christian; Jensen, Peter Ruhdal
Acetate kinase (ACK) (EC no: 188.8.131.52) interconverts acetyl-phosphate and acetate to either catabolize or synthesize acetyl-CoA dependent on the metabolic requirement. Among all ACK entries available in UniProt, we found that around 45% are multiple ACKs in some organisms including more than 300 species but surprisingly, little work has been done to clarify whether this has any significance. In an attempt to gain further insight we have studied the two ACKs (AckA1, AckA2) encoded by two neighboring genes conserved in Lactococcus lactis (L. lactis) by analyzing protein sequences, characterizing transcription structure, determining enzyme characteristics and effect on growth physiology. The results show that the two ACKs are most likely individually transcribed. AckA1 has a much higher turnover number and AckA2 has a much higher affinity for acetate in vitro. Consistently, growth experiments of mutant strains reveal that AckA1 has a higher capacity for acetate production which allows faster growth in an environment with high acetate concentration. Meanwhile, AckA2 is important for fast acetate-dependent growth at low concentration of acetate. The results demonstrate that the two ACKs have complementary physiological roles in L. lactis to maintain a robust acetate metabolism for fast growth at different extracellular acetate concentrations. The existence of ACK isozymes may reflect a common evolutionary strategy in bacteria in an environment with varying concentrations of acetate. PMID:24638105
Schell, William J. (Long Beach, CA)
A dry, fabric supported, polymeric gas separation membrane, such as cellulose acetate, is prepared by casting a solution of the polymer onto a shrinkable fabric preferably formed of synthetic polymers such as polyester or polyamide filaments before washing, stretching or calendering (so called griege goods). The supported membrane is then subjected to gelling, annealing, and drying by solvent exchange. During the processing steps, both the fabric support and the membrane shrink a preselected, controlled amount which prevents curling, wrinkling or cracking of the membrane in flat form or when spirally wound into a gas separation element.
Relation between mass transfer and operation parameters in the electrodialysis recovery of acetic acid
Lixin Yu; Tao Lin; Qingfeng Guo; Jihua Hao
The recovery of acetic acid from dilute wastewater by means of bipolar membrane electrodialysis is studied in more detail. The current efficiency of the electrodialysis recovery of acetic acid from dilute wastewater is related to the current density and other operation parameters. There exists a highest value of current efficiency at optimal current density. The highest concentration of recovered acid
Vinegar as a burn-down herbicide: Acetic acid concentrations, application volumes, and adjuvants
Technology Transfer Automated Retrieval System (TEKTRAN)
Acetic acid acts as a contact herbicide, injuring and killing plants by first destroying the cell membranes, which causes the rapid desiccation of the plant tissues. Vinegars with acetic acid concentrations of 11% or greater can burn the skin and cause serious to severe eye injury, including blindn...
Gel Electrophoresis Lab: DNA Fingerprinting
NSDL National Science Digital Library
Ehlers, Megan
This lab activity from the Biotechnology Alliance for Suncoast Biology Educators introduces the methods of RFLP analysis, or DNA fingerprinting, by using gel electrophoresis. Students will learn the role of restriction enzymes in DNA fingerprinting. Required materials, procedure and instructions are provided. This lesson plan may be downloaded in Microsoft Word document file format.
Gel Electrophoresis Lab: Paternity Case
NSDL National Science Digital Library
This lab activity from the Biotechnology Alliance for Suncoast Biology Educators provides instructions for conducting a gel electrophoresis lab. Students will try to solve a paternity case with this activity by obtaining a DNA fingerprint from each potential father, the mother and the child. This activity may be downloaded in PDF file format. A data collection sheet and student questions are also included.
Biocompatibility of dialysis membranes: Effects of chronic complement activation
Raymond M Hakim; Douglas T Fearon; J Michael Lazarus; Cynthia S Perzanowski
Biocompatibility of dialysis membranes: Effects of chronic complement activation. The ability of three dialysis membranes (cuprophane, cellulose acetate, and polymethylmethacrylate) to activate complement was studied prospectively in ten chronic dialysis patients using new and reused membranes. Patients were dialyzed for 1 month with each type of membrane. New cuprophane membranes caused the most intense activation, while polymethylmethacrylate (PMMA) surfaces caused
Electrophoresis. Author manuscript A versatile electrophoresis system for the analysis of high-and
Paris-Sud XI, Université de
sulfatepolyacrylamide gel electrophoresis of proteins in the relative molecular weight Mw range of 300,000-3000 Da processes. MESH Keywords Buffers ; Electrophoresis, Gel, Two-Dimensional ; methods ; Electrophoresis weight. To be analyzed with this electrophoresis system, high concentration gels are needed (example
Genetic distances in the tribe Bovini studied by gel electrophoresis
Butts, Kelley Elaine McRae
volts 7 applications end load ice in tank DIA4 cello gel ENO1 cellulose acetate 0. 10 M Trizma base 0. 05 M Boric acid pH 8. 2 0. 10 M Trizma base 0, 10 M Maleic anhydride 0. 01 M MgC12. 6H20 pH 7. 4 (*membrane buffer- I:3 dilution) 2... hours 100 volts 2-5 applications middle load room temperature 45 minutes 150 volts 1-3 applications end load ice in tank ESD cellulose acetate 0. 90 M Trizma base 0. 019 M Na4EDTA 0. 50 M Boric acid pH 8. 6 (*membrane and tank buffers-1...
Techniques For Focusing In Zone Electrophoresis
NASA Technical Reports Server (NTRS)
Sharnez, Rizwan; Twitty, Garland E.; Sammons, David W.
In two techniques for focusing in zone electrophoresis, force of applied electrical field in each charged particle balanced by restoring force of electro-osmosis. Two techniques: velocity-gradient focusing (VGF), suitable for rectangular electrophoresis chambers; and field-gradient focusing (FGF), suitable for step-shaped electrophoresis chambers.
Capillary Electrophoresis for the Analysis of Biopolymers
Krylov, Sergey
becoming available for some parts of proteomic research, but manually intensive slab-gel electrophoresis instruments will displace cumbersome slab-gel electrophoresis for protein analysis. We also believeCapillary Electrophoresis for the Analysis of Biopolymers Sergey N. Krylov and Norman J. Dovichi
Pre-Cast Gel Electrophoresis Guide
Kirschner, Marc W.
Novex® Pre-Cast Gel Electrophoresis Guide Version B January 27, 2003 IM-1002 Novex® Pre-Cast Gel Electrophoresis Guide General information and protocols for using Novex® pre-cast gels www.invitrogen.com tech.............................................................................................................................28 Electrophoresis of Novex® Pre-Cast Gels
Separation and determination of pseudoephedrine, dextromethorphan, diphenhydramine and chlorpheniramine in cold medicines by nonaqueous capillary electrophoresis
Yuming Dong; Xiaofeng Chen; Yonglei Chen; Xingguo Chen; Zhide Hu
An easy, rapid and simple nonaqueous capillary electrophoresis (NACE) method was developed for the identification and determination of four basic nitrogenous compounds, i.e. pseudoephedrine (PE), dextromethorphan (DXM), diphenhydramine (DHM) and chlorpheniramine (CLP). The most suitable running buffer was composed of 40mM ammonium acetate, 10% acetonitrile (ACN) in methanol with a fused-silica capillary column (47cm�75?m i.d.), 25kV applied voltage and 25�C
Membranes and Films from Polymers.
ERIC Educational Resources Information Center
Blumberg, Avrom A.
Provides background information on polymeric films and membranes including production methods, special industrial and medical applications, laboratory preparation, and an experimental investigation of a porous cellulose acetate membrane. Presents a demonstration to distinguish between high- and low-density polyethylene. (JM)
Electrophoresis 1994, IS, 591-615 Capillary electrophoresis of DNA in ultradilute polymer solutions 597 Annelise E. Barron
Barron, Annelise E.
Electrophoresis 1994, IS, 591-615 Capillary electrophoresis of DNA in ultradilute polymer solutions of California, Berkeley, CA A transient entanglement coupling mechanism for DNA separation by capillary electrophoresis in ultradilute polymer solutions Using capillary electrophoresis, large DNA molecules (2
Membrane humidity control investigation
NASA Technical Reports Server (NTRS)
Elam, J.; Ruder, J.; Strumpf, H.
The basic performance data on a hollow fiber membrane unit that removes water from a breathing gas loop by diffusion is presented. Using available permeability data for cellulose acetate, a preliminary design was made of a dehumidifier unit that would meet the problem statement.
Electrophoresis technology experiment MA-011
NASA Technical Reports Server (NTRS)
Allen, R. E.; Barlow, G. H.; Bier, M.; Bigazzi, P. E.; Knox, R. J.; Micale, F. J.; Seaman, G. V. F.; Vanderhoff, J. W.; Vanoss, C. J.; Patterson, W. J.
Experiment MA-011, electrophoresis technology, was designed to test electrophoresis hardware that would continue the development of technology for electrophoretic separation of materials in the near zero g environment of space. The experimental hardware generally functioned as planned. Frozen live cells were successfully transported into space, electrophoretic processing was performed, and viable cells were returned to earth. A separation of the three types of fixed red blood cells (rabbit, human, and horse) was demonstrated. The human lymphocytes, however, showed no apparent migration. The separation of human kidney cells produced the most exciting data. Analysis shows electrophoretic separation throughout the entire column with at least four bands of viable cells. The isotachophoresis experiment definitely demonstrated the isotachophoretic separation of biological cells in a near zero g environment.
Microchip capillary electrophoresis/electrochemistry.
Lacher, N A; Garrison, K E; Martin, R S; Lunte, S M
Microfabricated fluidic devices have generated considerable interest over the past ten years due to the fact that sample preparation, injection, separation, derivatization, and detection can be integrated into one miniaturized device. This review reports progress in the development of microfabricated analytical systems based on microchip capillary electrophoresis (CE) with electrochemical (EC) detection. Electrochemical detection has several advantages for use with microchip electrophoresis systems, for example, ease of miniaturization, sensitivity, and selectivity. In this review, the basic components necessary for microchip CEEC are described, including several examples of different detector configurations. Lastly, details of the application of this technique to the determination of catechols and phenols, amino acids, peptides, carbohydrates, nitroaromatics, polymerase chain reaction (PCR) products, organophosphates, and hydrazines are described. PMID:11519957
Electrophoresis in strong electric fields.
Barany, Sandor
Two kinds of non-linear electrophoresis (ef) that can be detected in strong electric fields (several hundred V/cm) are considered. The first ("classical" non-linear ef) is due to the interaction of the outer field with field-induced ionic charges in the electric double layer (EDL) under conditions, when field-induced variations of electrolyte concentration remain to be small comparatively to its equilibrium value. According to the Shilov theory, the non-linear component of the electrophoretic velocity for dielectric particles is proportional to the cubic power of the applied field strength (cubic electrophoresis) and to the second power of the particles radius; it is independent of the zeta-potential but is determined by the surface conductivity of particles. The second one, the so-called "superfast electrophoresis" is connected with the interaction of a strong outer field with a secondary diffuse layer of counterions (space charge) that is induced outside the primary (classical) diffuse EDL by the external field itself because of concentration polarization. The Dukhin-Mishchuk theory of "superfast electrophoresis" predicts quadratic dependence of the electrophoretic velocity of unipolar (ionically or electronically) conducting particles on the external field gradient and linear dependence on the particle's size in strong electric fields. These are in sharp contrast to the laws of classical electrophoresis (no dependence of V(ef) on the particle's size and linear dependence on the electric field gradient). A new method to measure the ef velocity of particles in strong electric fields is developed that is based on separation of the effects of sedimentation and electrophoresis using videoimaging and a new flowcell and use of short electric pulses. To test the "classical" non-linear electrophoresis, we have measured the ef velocity of non-conducting polystyrene, aluminium-oxide and (semiconductor) graphite particles as well as Saccharomice cerevisiae yeast cells as a function of the electric field strength, particle size, electrolyte concentration and the adsorbed polymer amount. It has been shown that the electrophoretic velocity of the particles/cells increases with field strength linearly up to about 100 and 200 V/cm (for cells) without and with adsorbed polymers both in pure water and in electrolyte solutions. In line with the theoretical predictions, in stronger fields substantial non-linear effects were recorded (V(ef)~E(3)). The ef velocity of unipolar ion-type conducting (ion-exchanger particles and fibres), electron-type conducting (magnesium and Mg/Al alloy) and semiconductor particles (graphite, activated carbon, pyrite, molybdenite) increases significantly with the electric field (V(ef)~E(2)) and the particle's size but is almost independent of the ionic strength. These trends are inconsistent with Smoluchowski's equation for dielectric particles, but are consistent with the Dukhin-Mishchuk theory of superfast electrophoresis. PMID:19041962
[Nomegestrol acetate: clinical pharmacology].
Lello, S
Progestogens are used in clinical practice in some conditions. Their effects depend on their chemical structure, pharmacokinetics, pharmacodynamics, with important differences among various progestogens. Generally, progestins are classified according to their parent molecule, of which often they keep some features. Derivatives of 19-nor-progesterone are characterized by high selectivity of action on progestin receptor. In particular, nomegestrol acetate (NomAc) shows an important progestational potency, neutral gluco-lipid profile, and antigonadotropic activity. It is used for treating menstrual cycle disorders and for hormone replacement therapy in menopause in association with an estrogen. In future, thanks to its antigonadotropic activity, NomAc will be used in estroprogestin combinations in fertile women, thus taking advantage of its tolerability profile and obtaining numerous non-contraceptive benefits as well. PMID:19749678
Capillary electrophoresis systems and methods
Dorairaj, Rathissh (Hillsboro, OR); Keynton, Robert S. (Louisville, KY); Roussel, Thomas J. (Louisville, KY); Crain, Mark M. (Georgetown, IN); Jackson, Douglas J. (New Albany, IN); Walsh, Kevin M. (Louisville, KY); Naber, John F. (Goshen, KY); Baldwin, Richard P. (Louisville, KY); Franco, Danielle B. (Mount Washington, KY)
An embodiment of the invention is directed to a capillary electrophoresis apparatus comprising a plurality of separation micro-channels. A sample loading channel communicates with each of the plurality of separation channels. A driver circuit comprising a plurality of electrodes is configured to induce an electric field across each of the plurality of separation channels sufficient to cause analytes in the samples to migrate along each of the channels. The system further comprises a plurality of detectors configured to detect the analytes.
Capillary electrophoresis-mass spectrometry
Jianyi Cai; Jack Henion
As an on-line separation method, capillary electrophoresis (CE)-mass spectrometry (MS) distinguishes analytes by both their differences in electrophoretic mobilities and structural information. CE-MS combines the advantages of CE and MS so that information on both high separation efficiency and molecular masses and\\/or fragmentation can be obtained in one analysis. During the past few years CE-MS has undergone significant development both
Molecular Structure of Phenylmercuric acetate
NSDL National Science Digital Library
Phenylmercuric acetate is white to white-yellow crystalline powder that is odorless. This phenyl mercury compound is used mainly as a fungicide, herbicide, slimicide and bacteriocide. Phenylmercuric acid serves as a preservative in canned paint, eye ointments and drops, injectable solutions, skin disinfectants and in cosmetics products such as hair shampoos, mouthwashes and toothpastes. It is also used in contraceptive gels and foams. Phenylmercuric acetate is prepared by interaction of benzene with mercuric acetate in glacial acetic acid. Phenylmercuric acetate's former production and use as a fungicide and as a mildew inhibitor in paints may have resulted in its direct release to the environment. This substance is very toxic to aquatic organisms and may be hazardous to the environment.
Scaleable production and separation of fermentation-derived acetic acid. Final CRADA report.
Snyder, S. W.; Energy Systems
Half of U.S. acetic acid production is used in manufacturing vinyl acetate monomer (VAM) and is economical only in very large production plants. Nearly 80% of the VAM is produced by methanol carbonylation, which requires high temperatures and exotic construction materials and is energy intensive. Fermentation-derived acetic acid production allows for small-scale production at low temperatures, significantly reducing the energy requirement of the process. The goal of the project is to develop a scaleable production and separation process for fermentation-derived acetic acid. Synthesis gas (syngas) will be fermented to acetic acid, and the fermentation broth will be continuously neutralized with ammonia. The acetic acid product will be recovered from the ammonium acid broth using vapor-based membrane separation technology. The process is summarized in Figure 1. The two technical challenges to success are selecting and developing (1) microbial strains that efficiently ferment syngas to acetic acid in high salt environments and (2) membranes that efficiently separate ammonia from the acetic acid/water mixture and are stable at high enough temperature to facilitate high thermal cracking of the ammonium acetate salt. Fermentation - Microbial strains were procured from a variety of public culture collections (Table 1). Strains were incubated and grown in the presence of the ammonium acetate product and the fastest growing cultures were selected and incubated at higher product concentrations. An example of the performance of a selected culture is shown in Figure 2. Separations - Several membranes were considered. Testing was performed on a new product line produced by Sulzer Chemtech (Germany). These are tubular ceramic membranes with weak acid functionality (see Figure 3). The following results were observed: (1) The membranes were relatively fragile in a laboratory setting; (2) Thermally stable {at} 130 C in hot organic acids; (3) Acetic acid rejection > 99%; and (4) Moderate ammonia flux. The advantages of producing acetic acid by fermentation include its appropriateness for small-scale production, lower cost feedstocks, low energy membrane-based purification, and lower temperature and pressure requirements. Potential energy savings of using fermentation are estimated to be approximately 14 trillion Btu by 2020 from a reduction in natural gas use. Decreased transportation needs with regional plants will eliminate approximately 200 million gallons of diesel consumption, for combined savings of 45 trillion Btu. If the fermentation process captures new acetic acid production, savings could include an additional 5 trillion Btu from production and 7 trillion Btu from transportation energy.
Capillary Electrophoresis Frontal Analysis for Characterization of rv 3 Integrin Binding
Chen, David D.Y.
Capillary Electrophoresis Frontal Analysis for Characterization of rv 3 Integrin Binding Columbia Vancouver, BC, Canada V6T 1Z3 The specific binding characteristics of rv 3 integrins of nonspecific binding. The rv 3 integrin, a membrane protein, was studied in solution, without the need
Charge Shift Electrophoresis: Simple Method for Distinguishing between Amphiphilic and Hydrophilic Proteins in Detergent Solution
Ari Helenius; Kai Simons
Seventeen hydrophilic proteins and five amphiphilic membrane proteins were subjected to agarose gel electrophoresis in the presence of a nonionic detergent (Triton X-100), a mixture of a nonionic and an anionic detergent (Triton X-100 and sodium deoxycholate), and a mixture of a nonionic and a cationic detergent (Triton X-100 and cetyltrimethylammonium bromide). The electrophoretic mobility of the hydrophilic proteins was
Mathematical models of continuous flow electrophoresis: Electrophoresis technology
NASA Technical Reports Server (NTRS)
Saville, Dudley A.
Two aspects of continuous flow electrophoresis were studied: (1) the structure of the flow field in continuous flow devices; and (2) the electrokinetic properties of suspended particles relevant to electrophoretic separations. Mathematical models were developed to describe flow structure and stability, with particular emphasis on effects due to buoyancy. To describe the fractionation of an arbitrary particulate sample by continuous flow electrophoresis, a general mathematical model was constructed. In this model, chamber dimensions, field strength, buffer composition, and other design variables can be altered at will to study their effects on resolution and throughput. All these mathematical models were implemented on a digital computer and the codes are available for general use. Experimental and theoretical work with particulate samples probed how particle mobility is related to buffer composition. It was found that ions on the surface of small particles are mobile, contrary to the widely accepted view. This influences particle mobility and suspension conductivity. A novel technique was used to measure the mobility of particles in concentrated suspensions.
Acetate treatment increases fatty acid content in LPS-stimulated BV2 microglia.
Bhatt, Dhaval P; Rosenberger, Thad A
Acetate supplementation increases plasma acetate, brain acetyl-CoA, histone acetylation, phosphocreatine levels, and is anti-inflammatory in models of neuroinflammation and neuroborreliosis. Although radiolabeled acetate is incorporated into the cellular lipid pools, the effect that acetate supplementation has on lipid deposition has not been quantified. To determine the impact acetate-treatment has on cellular lipid content, we investigated the effect of acetate in the presence of bacterial lipopolysaccharide (LPS) on fatty acid, phospholipid, and cholesterol content in BV2 microglia. We found that 1, 5, and 10 mM of acetate in the presence of LPS increased the total fatty acid content in BV2 cells by 23, 34, and 14 % at 2 h, respectively. Significant increases in individual fatty acids were also observed with all acetate concentrations tested with the greatest increases occurring with 5 mM acetate in the presence of LPS. Treatment with 5 mM acetate in the absence of LPS increased total cholesterol levels by 11 %. However, neither treatment in the absence of LPS significantly altered the content of individual phospholipids or total phospholipid content. To determine the minimum effective concentration of acetate we measured the time- and concentration-dependent changes in histone acetylation using western blot analysis. These studies showed that 5 mM acetate was necessary to induce histone acetylation and at 10 mM acetate, the histone acetylation-state increased as early as 0.5 h following the start of treatment. These data suggest that acetate increases fatty acid content in LPS-stimulated BV2 microglia that is reflected by an increase in fatty acids esterified into membrane phospholipids. PMID:24852320
Ulipristal acetate for emergency contraception.
Russo, J A; Creinin, M D
Ulipristal acetate is a progesterone receptor modulator. As an emergency contraceptive, a 30-mg micronized formulation is effective for use up to 120 h from unprotected sexual intercourse. Ulipristal acetate acts as an antagonist of the progesterone receptor at the transcriptional level and a competitive antagonist of glucocorticoid receptor function. In contrast to other contraceptives, it has little effect on sex hormone-binding globulin. Although a single small study demonstrated some potential endometrial effects after ulipristal acetate administration, the clinical relevance of these findings is unclear. The incidence of adverse events in clinical trials for emergency contraception has typically been minimal, with one study showing a higher than expected incidence of nausea upon ulipristal acetate use. Ulipristal acetate, like other emergency contraceptive products, can lengthen the time to the next expected menstruation. Ulipristal acetate may have several advantages over currently approved emergency contraceptives. When compared to levonorgestrel, ulipristal acetate maintains its efficacy for a full 120 h, whereas levonorgestrel formulations have declining efficacy over that time frame. Moreover, although the copper intrauterine device (IUD) is highly effective as an emergency contraceptive, accessibility is an issue since the IUD requires a skilled provider for insertion. PMID:20967297
Electromigration dispersion in Capillary Electrophoresis
Chen, Zhen; Ghosal, Sandip
In a previous paper (S. Ghosal and Z. Chen Bull. Math. Biol. 2010 72, pg. 2047) it was shown that the evolution of the solute concentration in capillary electrophoresis is described by a nonlinear wave equation that reduced to Burger�s equation if the nonlinearity was weak. It was assumed that only strong electrolytes (fully dissociated) were present. In the present paper it is shown that the same governing equation also describes the situation where the electrolytic buffer consists of a single weak acid (or base). A simple approximate formula is derived for the dimensionless peak variance which is shown to agree well with published experimental data. PMID:22147104
Integrated multiplexed capillary electrophoresis system
Yeung, Edward S. (Ames, IA); Tan, Hongdong (Ames, IA)
The present invention provides an integrated multiplexed capillary electrophoresis system for the analysis of sample analytes. The system integrates and automates multiple components, such as chromatographic columns and separation capillaries, and further provides a detector for the detection of analytes eluting from the separation capillaries. The system employs multiplexed freeze/thaw valves to manage fluid flow and sample movement. The system is computer controlled and is capable of processing samples through reaction, purification, denaturation, pre-concentration, injection, separation and detection in parallel fashion. Methods employing the system of the invention are also provided.
Improvement of productivity in acetic acid fermentation with Clostridium thermoaceticum
Shah, M.M.; Cheryan, M. [Univ. of Illinois, Urbana, IL (United States)
Production of acetic acid by a mutant strain of Clostridium thermoaceticum was compared in three types of membrane cell-recycle bioreactors. A modified fed-batch bioreactor (where the product is partially removed at the end of fermentation, but the cells are retained), and a two-stage CSTR (with product being removed continuously and the cells being recycled from the second to the first stage) resulted in better performance than a one-stage CSTR or batch fermenter. The difference in performance was greater at higher acetate concentration. With 45 g/L of glucose in the feed, productivity was 0.75-1.12 g/L-h and acetic acid concentrations were 34-38 g/L. This is more than double the batch system. The nutrient supply rate also appeared to have a strong influence on productivity of the microorganism.
Molecular Structure of Sodium acetate
NSDL National Science Digital Library
Sodium acetate is known for its ability to supercool. It freezes at 130 degrees, but can exist as a liquid at a much lower temperature. In order to melt solidified sodium acetate, however, every single crystal must liquify, otherwise the material will recrystallize. Sodium acetate has been used as a deicer for roads and runways. It is also used a component of buffer systems and in the manufacture of pharmaceuticals and heat pads. The compound is quite stable. It may act as an irritant and be harmful if inhaled or absorbed through the skin.
Ulipristal acetate: contraceptive or contragestive?
Keenan, Jeffrey A
Ulipristal acetate is the first selective progesterone receptor modulator approved for postcoital contraception in the US. It appears to be significantly more effective in inhibition of ovulation than other forms of emergency contraception. However, ulipristal acetate is structurally similar to mifepristone, and several lines of evidence suggest that a postfertilization mechanism of action is also operative. This mechanism of action is considered to be contragestive versus contraceptive. Ulipristal acetate administration is contraindicated in a known or suspected pregnancy; however, it could quite possibly be used as an effective abortifacient. Health-care providers should inform patients of the possibility of both mechanisms of action with use of this drug. PMID:21666088
Conducting polymer electrodes for gel electrophoresis.
Bengtsson, Katarina; Nilsson, Sara; Robinson, Nathaniel D
In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that ?-conjugated polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT) can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis) systems. In this report, we extend our previous result to gel electrophoresis, and show that electrodes containing PEDOT can be used with a commercial polyacrylamide gel electrophoresis system with minimal impact to the resulting gel image or the ionic transport measured during a separation. PMID:24586761
Separation of radiolabelled glycosaminoglycan oligosaccharides by polyacrylamide-gel electrophoresis.
Hampson, I N; Gallagher, J T
Glycosaminoglycan oligosaccharides generated by treatment of biosynthetically radiolabelled dermatan sulphate and hyaluronic acid with chondroitin AC lyase or testicular hyaluronidase may be resolved into a series of discrete bands by polyacrylamide-gel electrophoresis. Bands were identified by fixation in glacial acetic acid containing 20% (w/v) 2,5-diphenyloxazole followed by fluorography. The bands represented glycans which differed in size by one disaccharide unit. For the larger oligosaccharides (decasaccharides and above) of similar charge: mass ratio, there was a linear relationship between electrophoretic mobility and log Mr. However, the smaller species showed anomalous migration patterns. Consideration of the structures of the fragments produced by the different enzyme treatments suggests that copolymeric and homopolymeric oligosaccharides may be separated by polyacrylamide-gel electrophoresis. There are many potential applications of this technique, foremost amongst them being studies on the molecular size heterogeneity and patterns of enzyme-mediated depolymerization of native glycosaminoglycan chains and investigations into rates of polymer chain elongation and post-polymerization modification reactions so essential to glycosaminoglycan function. PMID:6477495
Purification and properties of a highly enantioselective l-menthyl acetate hydrolase from Burkholderia cepacia
Lijuan Yu; Yan Xu; Xiaowei Yu
A highly enantioselective l-menthyl acetate esterase was purified to homogeneity from Burkholderia cepacia ATCC 25416, with a recovery of 4.8% and a fold purification of 22.7. The molecular weight of the esterase was found to be 37kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The N-terminal amino acid sequence was �MGARTDA�, and there was no homology in contrast to other
Capillary electrophoresis for drug analysis
NASA Astrophysics Data System (ADS)
Lurie, Ira S.
Capillary electrophoresis (CE) is a high resolution separation technique which is amenable to a wide variety of solutes, including compounds which are thermally degradable, non-volatile and highly polar, and is therefore well suited for drug analysis. Techniques which have been used in our laboratory include electrokinetic chromatography (ECC), free zone electrophoresis (CZE) and capillary electrochromatography (CEC). ECC, which uses a charged run buffer additive which migrates counter to osmotic flow, is excellent for many applications, including, drug screening and analyses of heroin, cocaine and methamphetamine samples. ECC approaches include the use of micelles and charged cyclodextrins, which allow for the separation of complex mixtures. Simultaneous separation of acidic, neutral and basic solutes and the resolution of optical isomers and positional isomers are possible. CZE has been used for the analysis of small ions (cations and anions) in heroin exhibits. For the ECC and CZE experiments performed in our laboratory, uncoated capillaries were used. In contrast, CEC uses capillaries packed with high performance liquid chromatography stationary phases, and offers both high peak capacities and unique selectivities. Applications include the analysis of cannabinoids and drug screening. Although CE suffers from limited concentration sensitivity, it is still applicable to trace analysis of drug samples, especially when using injection techniques such as stacking, or detection schemes such as laser induced fluorescence and extended pathlength UV.
Biotechnology Curriculum Freshman Exploratory: Electrophoresis
NSDL National Science Digital Library
Kurtz, Mary Jane
Gel electrophoresis is used in many areas of biotechnology and forensics. It is based on the concept that mixtures of substances can be separated by electrical force. The direction and speed of migration through the field is dependent on several factors. All substances are made of molecules that can be positively charged, negatively charged or neutral. These characteristics can be used to separate molecules when they are placed in a gel that has an electrical field. The gels generally used are made of agarose, a purified version of agar used in making bacterial plates. These gels are a porous material that acts as a molecular sieve through which smaller molecules can move more easily than larger ones. They move toward the opposite charged side of the gel with smaller pieces of DNA moving farther from the well compared to larger pieces. In this activity, students will identify separate molecules in a mixture by exposing them to an electric field, determine the charge and size of a molecule by its movement in a gel, and explain the importance of electrophoresis as a tool in biotechnology. This activity may be downloaded in Microsoft Word Doc file format.
DNA Sequencing Using capillary Electrophoresis
Dr. Barry Karger
The overall goal of this program was to develop capillary electrophoresis as the tool to be used to sequence for the first time the Human Genome. Our program was part of the Human Genome Project. In this work, we were highly successful and the replaceable polymer we developed, linear polyacrylamide, was used by the DOE sequencing lab in California to sequence a significant portion of the human genome using the MegaBase multiple capillary array electrophoresis instrument. In this final report, we summarize our efforts and success. We began our work by separating by capillary electrophoresis double strand oligonucleotides using cross-linked polyacrylamide gels in fused silica capillaries. This work showed the potential of the methodology. However, preparation of such cross-linked gel capillaries was difficult with poor reproducibility, and even more important, the columns were not very stable. We improved stability by using non-cross linked linear polyacrylamide. Here, the entangled linear chains could move when osmotic pressure (e.g. sample injection) was imposed on the polymer matrix. This relaxation of the polymer dissipated the stress in the column. Our next advance was to use significantly lower concentrations of the linear polyacrylamide that the polymer could be automatically blown out after each run and replaced with fresh linear polymer solution. In this way, a new column was available for each analytical run. Finally, while testing many linear polymers, we selected linear polyacrylamide as the best matrix as it was the most hydrophilic polymer available. Under our DOE program, we demonstrated initially the success of the linear polyacrylamide to separate double strand DNA. We note that the method is used even today to assay purity of double stranded DNA fragments. Our focus, of course, was on the separation of single stranded DNA for sequencing purposes. In one paper, we demonstrated the success of our approach in sequencing up to 500 bases. Other application papers of sequencing up to this level were also published in the mid 1990's. A major interest of the sequencing community has always been read length. The longer the sequence read per run the more efficient the process as well as the ability to read repeat sequences. We therefore devoted a great deal of time to studying the factors influencing read length in capillary electrophoresis, including polymer type and molecule weight, capillary column temperature, applied electric field, etc. In our initial optimization, we were able to demonstrate, for the first time, the sequencing of over 1000 bases with 90% accuracy. The run required 80 minutes for separation. Sequencing of 1000 bases per column was next demonstrated on a multiple capillary instrument. Our studies revealed that linear polyacrylamide produced the longest read lengths because the hydrophilic single strand DNA had minimal interaction with the very hydrophilic linear polyacrylamide. Any interaction of the DNA with the polymer would lead to broader peaks and lower read length. Another important parameter was the molecular weight of the linear chains. High molecular weight (> 1 MDA) was important to allow the long single strand DNA to reptate through the entangled polymer matrix. In an important paper, we showed an inverse emulsion method to prepare reproducibility linear polyacrylamide polymer with an average MWT of 9MDa. This approach was used in the polymer for sequencing the human genome. Another critical factor in the successful use of capillary electrophoresis for sequencing was the sample preparation method. In the Sanger sequencing reaction, high concentration of salts and dideoxynucleotide remained. Since the sample was introduced to the capillary column by electrokinetic injection, these salt ions would be favorably injected into the column over the sequencing fragments, thus reducing the signal for longer fragments and hence reading read length. In two papers, we examined the role of individual components from the sequencing reaction and then developed a protocol to reduce the deleterio
Allison Lab Protocol: Gel Electrophoresis, 1/2008, Steve Allison Gel Electrophoresis of Nucleic Acids
German, Donovan P.
Allison Lab Protocol: Gel Electrophoresis, 1/2008, Steve Allison Gel Electrophoresis of Nucleic the Polaroid camera to take a photo of the gel. · Note the electrophoresis conditions on the gel photo and tape Acids · Always wear gloves; ethidium bromide is a powerful mutagen! · For a 1.5% gel in the small gel
Improved Isolation Procedures for the Purple Membrane of Halobacterium Halobium
Brian M. Becher; Seph Y. Cassim
Techniques for purifying the purple membrane of Halobacterium halobium are given. This purple membrane contains a chromoprotein with a retinal prosthetic group similar to rhodopsin, the chromoprotein found in the visual systems of higher invertebrates and vertebrates. The described purple membrane isolation procedures yield a highly purified preparation as determined by transmitting electron microscopy and gel electrophoresis. Critical analysis of
Molecular Structure of Acetic acid
NSDL National Science Digital Library
Acetic Acid commonly associated with vinegar; it is the most commercially important organic acid and is used to manufacture a wide range of chemical products, such as plastics and insecticides. Acetic acid is produced naturally by Aceto bacteria but, except for making vinegar, is usually made through synthetic processes. Ethanoic acid is used as herbicide, as a micro-biocide, as a fungicide and for pH adjustment.
Hydrolysis of ethyl acetate:a pervaporation study
Habib I. Shaban
The influence of temperature on the separation factor, diffusion process, permeation rate, and permeability coefficient (k) for hydrolysis of ethyl acetate using a standard poly(vinyl alcohol) (PVA) membrane by pervaporation was investigated. The preliminary data presented in this work was obtained using a simple pervaporation technique built in-house. The experiments were conducted at 80, 65, 50 and 35�C. The initial
Compensating for Electro-Osmosis in Electrophoresis
NASA Technical Reports Server (NTRS)
Rhodes, Percy H.; Snyder, Robert S.
Simple mechanical adjustment eliminates transverse velocity component. New apparatus for moving-wall electrophoresis increases degree of collimation of chemical species in sample stream. Electrophoresis chamber set at slight angle in horizontal plane to adjust angle between solution flow and wall motion. Component of velocity created cancels electro-osmotic effect.
Fluorescence detection for gel and capillary electrophoresis
Hogan, B.
First, an indirect fluorescence detection system for the separation of proteins via gel electrophoresis. Quantities as low as 50 nanograms of bovine serum albumin and soybean trypsin inhibitor are separated and detected visually without the need for staining of the analytes. This is very similar to levels of protein commonly separated with gel electrophoresis.
Getting the Most out of Electrophoresis Units
ERIC Educational Resources Information Center
Mulvihill, Charlotte
At Oklahoma City Community College, they have developed gel electrophoresis activities that support active learning of many scientific concepts, including: pH, electrolysis, oxidation reduction, electrical currents, potentials, conductivity, molarity, gel electrophoresis, DNA and protein separation, and DNA fingerprinting. This article presents�
Electrophoresis-mass spectrometry probe
Andresen, Brian D. (Pleasanton, CA); Fought, Eric R. (Livermore, CA)
The invention involves a new technique for the separation of complex mixtures of chemicals, which utilizes a unique interface probe for conventional mass spectrometers which allows the electrophoretically separated compounds to be analyzed in real-time by a mass spectrometer. This new chemical analysis interface, which couples electrophoresis with mass spectrometry, allows complex mixtures to be analyzed very rapidly, with much greater specificity, and with greater sensitivity. The interface or probe provides a means whereby large and/or polar molecules in complex mixtures to be completely characterized. The preferred embodiment of the probe utilizes a double capillary tip which allows the probe tip to be continually wetted by the buffer, which provides for increased heat dissipation, and results in a continually operating interface which is more durable and electronically stable than the illustrated single capillary tip probe interface.
Electrophoresis-mass spectrometry probe
Andresen, B.D.; Fought, E.R.
The invention involves a new technique for the separation of complex mixtures of chemicals, which utilizes a unique interface probe for conventional mass spectrometers which allows the electrophoretically separated compounds to be analyzed in real-time by a mass spectrometer. This new chemical analysis interface, which couples electrophoresis with mass spectrometry, allows complex mixtures to be analyzed very rapidly, with much greater specificity, and with greater sensitivity. The interface or probe provides a means whereby large and/or polar molecules in complex mixtures to be completely characterized. The preferred embodiment of the probe utilizes a double capillary tip which allows the probe tip to be continually wetted by the buffer, which provides for increased heat dissipation, and results in a continually operating interface which is more durable and electronically stable than the illustrated single capillary tip probe interface. 8 figs.
Two Electrophoresis Experiments for Freshmen in the Health Professions.
ERIC Educational Resources Information Center
Brabson, G. Dana; Waugh, David S.
Describes procedures involved with paper electrophoresis separation of amino acids, gel electrophoresis separation of DNA, and design of an electrophoresis tank. Describes experiments using paper (amino acids) and gel (deoxyribonucleic acid fragments). Provides material lists, procedures, and discussion. (JM)
Polymeric matrices for DNA sequencing by capillary electrophoresis
Barron, Annelise E.
Polymeric matrices for DNA sequencing by capillary electrophoresis We review the wide range of polymeric materials that have been employed for DNA sequencing separations by capillary electrophoresis-linked polymer networks. Keywords: DNA sequencing / Capillary electrophoresis / Polymer solutions / Matrices
Edinburgh Research Explorer Native gel electrophoresis of human telomerase distinguishes
Millar, Andrew J.
Edinburgh Research Explorer Native gel electrophoresis of human telomerase distinguishes active Bihan, T & Harrington, L 2012, 'Native gel electrophoresis of human telomerase distinguishes active and investigate your claim. Download date: 16. Jun. 2014 #12;Native gel electrophoresis of human telomerase
Lights, Camera, Action! Systematic Variation in Difference Gel Electrophoresis
Lights, Camera, Action! Systematic Variation in Difference Gel Electrophoresis Kimberly F Abstract Two-dimensional Difference Gel Electrophoresis (DIGE) circumvents many of the prob- lems classical, single-dye gel electrophoresis images. Department of Statistics, Carnegie Mellon University
Nanodisc-solubilized membrane protein library reflects the membrane proteome.
Marty, Michael T; Wilcox, Kyle C; Klein, William L; Sligar, Stephen G
The isolation and identification of unknown membrane proteins offers the prospect of discovering new pharmaceutical targets and identifying key biochemical receptors. However, interactions between membrane protein targets and soluble ligands are difficult to study in vitro due to the insolubility of membrane proteins in non-detergent systems. Nanodiscs, nanoscale discoidal lipid bilayers encircled by a membrane scaffold protein belt, have proven to be an effective platform to solubilize membrane proteins and have been used to study a wide variety of purified membrane proteins. This report details the incorporation of an unbiased population of membrane proteins from Escherichia coli membranes into Nanodiscs. This solubilized membrane protein library (SMPL) forms a soluble in vitro model of the membrane proteome. Since Nanodiscs contain isolated proteins or small complexes, the SMPL is an ideal platform for interactomics studies and pull-down assays of membrane proteins. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the protein population before and after formation of the Nanodisc library indicates that a large percentage of the proteins are incorporated into the library. Proteomic identification of several prominent bands demonstrates the successful incorporation of outer and inner membrane proteins into the Nanodisc library. PMID:23400332
Micelles Protect and Concentrate Activated Acetic Acid
NASA Astrophysics Data System (ADS)
Todd, Zoe; House, C.
As more and more exoplanets are discovered and the habitability of such planets is considered, one can turn to searching for the origin of life on Earth in order to better understand what makes a habitable planet. Activated acetic acid, or methyl thioacetate, has been proposed to be central to the origin of life on Earth, and also as an important energy currency molecule in early cellular evolution. We have investigated the hydrolysis of methyl thioacetate under various conditions. Its uncatalyzed rate of hydrolysis is about three orders of magnitude faster (K = 0.00663 s^-1; 100�C, pH 7.5, concentration = 0.33mM) than published rates for its catalyzed production making it unlikely to accumulate under prebiotic conditions. However, we also observed that methyl thioacetate was protected from hydrolysis when inside its own hydrophobic droplets. We found that methyl thioacetate protection from hydrolysis was also possible in droplets of hexane and in the membranes of nonanoic acid micelles. Thus, the hydrophobic regions of prebiotic micelles and early cell membranes could have offered a refuge for this energetic molecule increasing its lifetime in close proximity to the reactions for which it would be needed. Methyl thioacetate could thus be important for the origin of life on Earth and perhaps for better understanding the potential habitability of other planets.
Biodegradable cellulose acetate nanofiber fabrication via electrospinning.
Christoforou, Theopisti; Doumanidis, Charalabos
Nanofiber manufacturing is one of the key advancements in nanotechnology today. Over the past few years, there has been a tremendous growth of research activities to explore electrospinning for nanofiber formation from a rich variety of materials. This quite simple and cost effective process operates on the principle that the solution is extracted under the action of a high electric field. Once the voltage is sufficiently high, a charged jet is ejected following a complicated looping trajectory. During its travel, the solvent evaporates leaving behind randomly oriented nanofibers accumulated on the collector. The combination of their nanoscale dimensionality, high surface area, porosity, flexibility and superior strength makes the electrospun fibers suitable for several value-added applications, such as filters, protecting clothes, high performance structures and biomedical devices. In this study biodegradable cellulose acetate (CA) nanofibrous membranes were produced using electrospinning. The device utilized consisted of a syringe equipped with a metal needle, a microdialysis pump, a high voltage supply and a collector. The morphology of the yielded fibers was determined using SEM. The effect of various parameters, including electric field strength, tip-to-collector distance, solution feed rate and composition on the morphological features of the electrospun fibers was examined. The optimum operating conditions for the production of uniform, non-beaded fibers with submicron diameter were also explored. The biodegradable CA nanofiber membranes are suitable as tissue engineering scaffolds and as reinforcements of biopolymer matrix composites in foils by ultrasonic welding methods. PMID:21133179
Palladium modified porous polymeric membranes and their performance in selective hydrogenation of propyne
Silke Ziegler; Juliane Theis; Detlev Fritsch
The accessible pore system of polymeric ultrafiltration membranes was modified by titanium dioxide and treated further with palladium acetate to yield catalytically active, porous nanofiltration membranes. This procedure is in general applicable for any polymeric ultrafiltration membrane. To overcome the drawback of low thermal stability of common polymeric membranes, new ultrafiltration membranes were developed, based on a polyamideimide containing up
Electrophoresis in space at zero gravity
NASA Technical Reports Server (NTRS)
Bier, M.; Snyder, R. S.
Early planning for manufacturing operations in space include the use of electrophoresis for purification and separation of biological materials. Greatly simplified electrophoresis apparatus have been flown in the Apollo 14 and 16 missions to test the possibility of stable liquid systems in orbit. Additionally, isoelectric focusing and isotachophoresis are of particular interest as they offer very high resolution and have self-sharpening boundaries. The value of possible space electrophoresis is substantial. For example, present technology permits large fractionation of only a few of blood proteins many fractions, and separated cell populations are needed for research.
Atomic Force Controlled Capillary Electrophoresis
NASA Astrophysics Data System (ADS)
Lewis, Aaron; Yeshua, Talia; Palchan, Mila; Lovsky, Yulia; Taha, Hesham
Lithography based on scanning probe microscopic techniques has considerable potential for accurate & localized deposition of material on the nanometer scale. Controlled deposition of metallic features with high purity and spatial accuracy is of great interest for circuit edit applications in the semiconductor industry, for plasmonics & nanophotonics and for basic research in surface enhanced Raman scattering & nanobiophysics. Within the context of metal deposition we will review the development of fountain pen nanochemistry and its most recent emulation Atomic Force Controlled Capillary Electrophoresis (ACCE). Using this latter development we will demonstrate achievement of unprecedented control of nanoparticle deposition using a three-electrode geometry. Three electrodes are attached: one on the outside of a metal coated glass probe, one on the inside of a hollow probe in a solution containing Au nanoparticles in the capillary, and a third on the surface where the writing takes place. The three electrodes provide electrical pulses for accurate control of deposition and retraction of the liquid from the surface overcoming the lack of control seen in both dip pen lithography & fountain pen nanochemistry when the tip contacts the surface. With this development, we demonstrate depositing a single 1.3 nm Au nanoparticle onto surfaces such as semiconductors.
Desmopressin Acetate in Intracranial Haemorrhage
Kapapa, Thomas; R�hrer, Stefan; Struve, Sabine; Petscher, Matthias; K�nig, Ralph; Wirtz, Christian Rainer; Woischneck, Dieter
Introduction. The secondary increase in the size of intracranial haematomas as a result of spontaneous haemorrhage or trauma is of particular relevance in the event of prior intake of platelet aggregation inhibitors. We describe the effect of desmopressin acetate as a means of temporarily stabilising the platelet function. Patients and Methods. The platelet function was analysed in 10 patients who had received single (N = 4) or multiple (N = 6) doses of acetylsalicylic acid and 3 patients (control group) who had not taken acetylsalicylic acid. All subjects had suffered intracranial haemorrhage. Analysis was performed before, half an hour and three hours after administration of desmopressin acetate. Statistical analysis was performed by applying a level of significance of P ? 0.05. Results. (1) Platelet function returned to normal 30 minutes after administration of desmopressin acetate. (2) The platelet function worsened again after three hours. (3) There were no complications related to electrolytes or fluid balance. Conclusion. Desmopressin acetate can stabilise the platelet function in neurosurgical patients who have received acetylsalicylic acid prior to surgery without causing transfusion-related side effects or a loss of time. The effect is, however, limited and influenced by the frequency of drug intake. Further controls are needed in neurosurgical patients. PMID:25610644
Concentrating aqueous acetate solutions with tertiary amines
Lee, Champion
= I'7o(w/wk) 11 Liquid-liquid equilibrium data for the calcium acetate/water/amuie system with various extractants. (T= TEA, D= DEMA. Initial aqueous-phase calcium acetate concentration= 2%(w/w). ) 27 28 31 34 via FIGURE Page 12 Liquid.... (Calcium acetate/water /amine, TEA:DEMA= I mL:2 mL, initial aqueous calcium acetate= 1% (w/w). ) Equilibrium calcium acetate concentrations in the aqueous phase determined by FTIR and AA measurements. (Calcium acetate/water /amine, TEA:DEMA= I mL;2 m...
Study of disposable microdevices for DNA electrophoresis
Timp, Winston (Winston G.)
A study was undertaken to determine if a microfluidic chip, made of economical plastic materials, is feasible. The chip was designed to perform gel electrophoresis, specifically of DNA fragments for either sequencing or ...
Capillary electrophoresis electrospray ionization mass spectrometry interface
Smith, Richard D. (Richland, WA); Severs, Joanne C. (Hayward, CA)
The present invention is an interface between a capillary electrophoresis separation capillary end and an electrospray ionization mass spectrometry emitter capillary end, for transporting an anolyte sample from a capillary electrophoresis separation capillary to a electrospray ionization mass spectrometry emitter capillary. The interface of the present invention has: (a) a charge transfer fitting enclosing both of the capillary electrophoresis capillary end and the electrospray ionization mass spectrometry emitter capillary end; (b) a reservoir containing an electrolyte surrounding the charge transfer fitting; and (c) an electrode immersed into the electrolyte, the electrode closing a capillary electrophoresis circuit and providing charge transfer across the charge transfer fitting while avoiding substantial bulk fluid transfer across the charge transfer fitting. Advantages of the present invention have been demonstrated as effective in providing high sensitivity and efficient analyses.
High-performance capillary electrophoresis of histones
Gurley, L.R.; London, J.E.; Valdez, J.G.
A high performance capillary electrophoresis (HPCE) system has been developed for the fractionation of histones. This system involves electroinjection of the sample and electrophoresis in a 0.1M phosphate buffer at pH 2.5 in a 50 {mu}m {times} 35 cm coated capillary. Electrophoresis was accomplished in 9 minutes separating a whole histone preparation into its components in the following order of decreasing mobility; (MHP) H3, H1 (major variant), H1 (minor variant), (LHP) H3, (MHP) H2A (major variant), (LHP) H2A, H4, H2B, (MHP) H2A (minor variant) where MHP is the more hydrophobic component and LHP is the less hydrophobic component. This order of separation is very different from that found in acid-urea polyacrylamide gel electrophoresis and in reversed-phase HPLC and, thus, brings the histone biochemist a new dimension for the qualitative analysis of histone samples. 27 refs., 8 figs.
Analysis of Simple Carbohydrates by Capillary Electrophoresis and Capillary Electrophoresis�Mass Spectrometry
Christian W. Klampfl; Markus Himmelsbach; Wolfgang Buchberger
\\u000a An overview of the application of capillary electrophoresis and �capillary electrophoresis�mass spectrometry in the analysis\\u000a of simple carbohydrates without any previous derivatization step is given. Besides electrolyte systems for �carbohydrate separation,\\u000a detection techniques employed in capillary electrophoresis, such as �spectrophotometric detection, electrochemical detection,\\u000a and mass spectrometric �detection, are discussed, as are less common detection techniques. Thus, the chapter focuses on
Alcohol dehydrogenase of acetic acid bacteria: structure, mode of action, and applications in biotechnology
Toshiharu Yakushi; Kazunobu Matsushita
Pyrroquinoline quinone-dependent alcohol dehydrogenase (PQQ-ADH) of acetic acid bacteria is a membrane-bound enzyme involved\\u000a in the acetic acid fermentation by oxidizing ethanol to acetaldehyde coupling with reduction of membranous ubiquinone (Q),\\u000a which is, in turn, re-oxidized by ubiquinol oxidase, reducing oxygen to water. PQQ-ADHs seem to have co-evolved with the organisms\\u000a fitting to their own habitats. The enzyme consists of
Nonradioactive monitoring of organic and inorganic solute transport into single Xenopus oocytes by capillary zone electrophoresis.
Nussberger, S; Foret, F; Hebert, S C; Karger, B L; Hediger, M A
Transport of organic and inorganic solutes into and out of cells requires specialized transport proteins. Given a sufficiently sensitive analytical method for measuring cellular solute concentrations, it should be possible to monitor solute transport across the plasma membrane at the level of single cells. We report a capillary zone electrophoresis approach that is generally applicable to monitor solute transport into Xenopus laevis oocytes, requires only nanoliters of sample, and involves no radioactive materials. The sensitivity of capillary electrophoresis with UV detection is typically on the order of 10(-5)-10(-6) M, resulting in the mass detection limits in the low femtomole range. We show that capillary zone electrophoresis serves as a simple technique to measure solute transport into oocytes. Studies of the mammalian oligopeptide transporter PepT1 and the Na(+)- and K(+)-coupled epithelial and neuronal glutamate transporter EAAC1 expressed in oocytes demonstrate that transport of the dipeptide Trp-Gly via PepT1 and transport of Na+ and K+ via EAAC1 across the oocyte plasma membrane can be monitored by measuring intracellular tryptophan absorption and by indirect UV detection of inorganic ions, respectively. The CZE method allowed the simultaneous detection of changes of intracellular Na+ and K+ concentrations in response to EAAC1-mediated Na+ cotransport and K+ countertransport. This is the first report of a capillary zone electrophoresis-based quantitative analysis of intracellular components of a single cell in response to transport activity. Images FIGURE 1 FIGURE 6 PMID:8789117
Affinity Electrophoresis Using Ligands Attached To Polymers
NASA Technical Reports Server (NTRS)
Van Alstine, James M.; Snyder, Robert S.; Harris, J. M.; Brooks, D. E.
In new technique, reduction of electrophoretic mobilities by addition of polyethylene glycol to ligands increases electrophoretic separabilities. In immuno-affinity electrophoresis, modification of ligands extends specificity of electrophoretic separation to particles having surface electric-charge structures otherwise making them electrophoretically inseparable. Modification of antibodies by polyethylene glycol greatly reduces ability to aggregate while enhancing ability to affect electrophoretic mobilities of cells. In hydrophobic-affinity electrophoresis, addition of polyethylene glycol reduces tendency toward aggregation of cells or macromolecules.
SDS Polyacrylamide Gel Electrophoresis Gel Recipes
Pike, Linda J.
SDS Polyacrylamide Gel Electrophoresis Gel Recipes % Acrylamide 5% 7.5% 10.% 12.5% 15% 18% 4 for running gel; ~10 ml for stacking gel Electrophoresis Buffer: 5X Buffer: 1 X Buffer 60 g Tris base 9 g Tris% Stacking Gel 30% Acrylamide (ml) 5.0 7.5 10.0 12.5 15.0 18.0 1.3 1% Bisacrylamide (ml) 7.8 5.8 3.9 3.1 3
Pulsed field gel electrophoresis for bifidobacterium.
Jim�nez, Esther; G�mez, Marta; Moles, Laura
Pulse Field Gel Electrophoresis (PFGE), unlike conventional electrophoresis, can resolve DNA fragments greater than 30 kb and is a highly discriminatory molecular typing method. Here we describe a PFGE protocol for bifidobacteria characterized by a short lysis time determined by the addition of lysis reagents to the initial cell suspension, a reduced incubation period of the plugs in proteinase K, and an improved washing plug step with preheating of the buffer in a shaking incubator. PMID:25862062
Vibrational spectroscopy and electrophoresis as a "golden means" in monitoring of polysaccharides in medical plant and gels
NASA Astrophysics Data System (ADS)
Pielesz, A.
In recent years, some bioactive polysaccharides isolated from natural sources have attracted much attention in the field of biochemistry and pharmacology. Of them, polysaccharides or their glycoconjugates were shown to exhibit multiple biological activities including anticarcinogenic, anticoagulant, immunostimulating, antioxidant, etc. Pharmacotherapy using plant-derived substances can be currently regarded as a very promising future alternative to conventional therapy. The advanced biotechnologies available today enable chemical investigation of well-defined bioactive plant components as sources of novel drugs. The need for safer drugs without side effects has led to the use of natural ingredients with proven safety. Special interest is focused on plant polysaccharides. This article attempts to review the current structural and conformational characterization of some importantly bioactive monosaccharides isolated from following plant cell-wall: Symphytum officinale (comfrey), Thymus pulegioides (thyme), Trigonella foenum-graecum L. (fenugreek), Tussilago farfara L. (coltsfoot), Hyssopus officinalis (hyssop), Althaea officinalis L. (marshmallow) and Equisetum arvense L. (horsetail). The chemical structures of monosaccharides were analysed using FTIR and Raman spectroscopies as well as cellulose acetate membrane electrophoresis (CAE). The dried plant samples were gently hydrolysed with sulphuric acid. The presence of glucuronic acid, galacturonic acid, alginic acid, glucose, mannose and xylose in the hydrolysates of reference substances and non-defatted plant films was proved. The possibility of a taxonomic classification of plant cell walls based on infrared and Raman spectroscopies and the use of spectral fingerprinting for authentication and detection of adulteration of products rich in cell-wall materials are discussed. Individual bands were selected to monitor the sugar content in medical plant cell walls and to confirm the identity of the analysed plants.
Fragrance material review on p-anisyl acetate.
McGinty, D; Letizia, C S; Api, A M
A toxicologic and dermatologic review of p-anisyl acetate when used as a fragrance ingredient is presented. p-Anisyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for p-anisyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, and genotoxicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22417777
Fragrance material review on 2,4-dimethylbenzyl acetate.
McGinty, D; Letizia, C S; Api, A M
A toxicologic and dermatologic review of 2,4-dimethylbenzyl acetate when used as a fragrance ingredient is presented. 2,4-Dimethylbenzyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, iso-butyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2,4-dimethylbenzyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, and skin sensitization data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22414641
A Prototype Two-Dimensional Capillary Electrophoresis System Fabricated in
Prentiss, Mara
gel electrophoresis in a capillary format is presented. In this method, separation in the first electrophoresis.6,7 One-dimensional (1D) gel electrophoresis (in the form of SDS-PAGE) is still used for separations of proteins, but 1D gels are increasingly being replaced by capillary electrophoresis.8
[Advances in functional genomics studies underlying acetic acid tolerance of Saccharomyces cerevisiae].
Zhao, Xinqing; Zhang, Mingming; Xu, Guihong; Xu, Jianren; Bai, Fengwu
Industrial microorganisms are subject to various stress conditions, including products and substrates inhibitions. Therefore, improvement of stress tolerance is of great importance for industrial microbial production. Acetic acid is one of the major inhibitors in the cellulosic hydrolysates, which affects seriously on cell growth and metabolism of Saccharomyces cerevisiae. Studies on the molecular mechanisms underlying adaptive response and tolerance of acetic acid of S. cerevisiae benefit breeding of robust strains of industrial yeast for more efficient production. In recent years, more insights into the molecular mechanisms underlying acetic acid tolerance have been revealed through analysis of global gene expression and metabolomics analysis, as well as phenomics analysis by single gene deletion libraries. Novel genes related to response to acetic acid and improvement of acetic acid tolerance have been identified, and novel strains with improved acetic acid tolerance were constructed by modifying key genes. Metal ions including potassium and zinc play important roles in acetic acid tolerance in S. cerevisiae, and the effect of zinc was first discovered in our previous studies on flocculating yeast. Genes involved in cell wall remodeling, membrane transport, energy metabolism, amino acid biosynthesis and transport, as well as global transcription regulation were discussed. Exploration and modification of the molecular mechanisms of yeast acetic acid tolerance will be done further on levels such as post-translational modifications and synthetic biology and engineering; and the knowledge obtained will pave the way for breeding robust strains for more efficient bioconversion of cellulosic materials to produce biofuels and bio-based chemicals. PMID:25007573
Quantification of Fumaria officinalis isoquinoline alkaloids by nonaqueous capillary electrophoresis-electrospray ion trap mass spectrometry.
Sturm, Sonja; Strasser, Eva-Maria; Stuppner, Hermann
A capillary electrophoresis (CE) method using non-aqueous (NA) separation solutions combined with an ion trap mass spectrometer (MS and MS/MS) as detection device is presented for the separation, identification and quantification of isoquinoline alkaloids from Fumaria officinalis. The best results were obtained with a mixture of acetonitrile-methanol (9:1, v/v) containing 60mM ammonium acetate and 2.2M acetic acid as running electrolyte and an applied voltage of 30 kV. Electrospray MS measurements were performed in the positive ionization mode with isopropanol-water (1:1, v/v) as sheath liquid at a flow rate of 3 microl/min. Alkaloids were detected as [M+H](+)-ions and showed typical fragmentation patterns in MS/MS experiments. The developed assay was used for the quantification of seven isoquinoline alkaloids representing different structural subtypes in Fumariae herba extracts and F. herba containing phytopharmaceuticals. PMID:16378615
Ozone decomposition in aqueous acetate solutions
Sehested, K.; Holcman, J.; Bjergbakke, E.; Hart, E.J.
The acetate radical ion reacts with ozone with a rate constant of k = (1.5 +/- 0.5) x 10Z dmT mol s . The products from this reaction are CO2, HCHO, and O2 . By subsequent reaction of the peroxy radical with ozone the acetate radical ion is regenerated through the OH radical. A chain decomposition of ozone takes place. It terminates when the acetate radical ion reacts with oxygen forming the unreactive peroxy acetate radical. The chain is rather short as oxygen is developed, as a result of the ozone consumption. The inhibiting effect of acetate on the ozone decay is rationalized by OH scavenging by acetate and successive reaction of the acetate radical ion with oxygen. Some products from the bimolecular disappearance of the peroxy acetate radicals, however, react further with ozone, reducing the effectiveness of the stabilization.
Recent advances in affinity capillary electrophoresis for binding studies.
Albishri, Hassan M; El Deeb, Sami; AlGarabli, Noura; AlAstal, Raghda; Alhazmi, Hassan A; Nachbar, Markus; El-Hady, Deia Abd; W�tzig, Hermann
The present review covers recent advances and important applications of affinity capillary electrophoresis (ACE). It provides an overview about various ACE types, including ACE-MS, the multiple injection mode, the use of microchips and field-amplified sample injection-ACE. The most common scenarios of the studied affinity interactions are protein-drug, protein-metal ion, protein-protein, protein-DNA, protein-carbohydrate, carbohydrate-drug, peptide-peptide, DNA-drug and antigen-antibody. Approaches for the improvements of ACE in term of precision, rinsing protocols and sensitivity are discussed. The combined use of computer simulation programs to support data evaluation is presented. In conclusion, the performance of ACE is compared with other techniques such as equilibrium dialysis, parallel artificial membrane permeability assay, high-performance affinity chromatography as well as surface plasmon resonance, ultraviolet, circular dichroism, nuclear magnetic resonance, Fourier transform infrared, fluorescence, MS and isothermal titration calorimetry. PMID:25534793
Genera and species in acetic acid bacteria
Yuzo Yamada; Pattaraporn Yukphan
Taxonomic studies of acetic acid bacteria were historically surveyed. The genus Acetobacter was first introduced in 1898 with a single species, Acetobacter aceti. The genus Gluconobacter was proposed in 1935 for strains with intense oxidation of glucose to gluconic acid rather than oxidation of ethanol to acetic acid and no oxidation of acetate. The genus �Acetomonas\\
Organic compounds passage through RO membranes
Dan Libotean; Jaume Giralt; Robert Rallo; Yoram Cohen; Francesc Giralt; Harry F. Ridgway; Grisel Rodriguez; Don Phipps
Organic solute permeation, sorption, and rejection by reverse osmosis membranes, from aqueous solutions, were studied experimentally and via artificial neural networks (ANN)-based quantitative structure�property relations (QSPR), for a set of fifty organic compounds for polyamide and cellulose acetate membranes. Membrane solute sorption and passage for dead-end filtration model experiments were quantified based on radioactivity measurements for radiolabeled compounds in the
Application of denaturing gradient gel electrophoresis (DGGE) and temperature gradient gel electrophoresis (TGGE) in microbial ecology
Gerard Muyzer; Kornelia Smalla
Here, the state of the art of the application of denaturing gradient gel electrophoresis (DGGE) and temperature gradient gel electrophoresis (TGGE) in microbial ecology will be presented. Furthermore, the potentials and limitations of these techniques will be discussed, and it will be indicated why their use in ecological studies has become so important. Abbreviations: ARDRA - amplified ribosomal DNA restriction
Denaturation and electrophoresis of RNA with formaldehyde.
Rio, Donald C
Electrophoretic size fractionation can be used to denature and separate large mRNA molecules (0.5-10 kb) on formaldehyde-containing agarose gels. Formaldehyde contains a carbonyl group that reacts to form Schiff bases with the imino or amino groups of guanine, adenine, and cytosine. These covalent adducts prevent normal base pairing and maintain the RNA in a denatured state. Because these adducts are unstable, formaldehyde must be present in the gel to maintain the RNA in the denatured state. This protocol describes the preparation of an agarose gel with formaldehyde and its setup in a horizontal electrophoresis apparatus. RNA samples are prepared and denatured in a solution of formamide and formaldehyde and, with 0.5- to 10-kb size markers, subjected to electrophoresis through the gel. Following electrophoresis, the gel is stained to visualize RNA markers or rRNA using one of several different types of stains. PMID:25646498
Free flow cell electrophoresis using zwitterionic buffer
NASA Technical Reports Server (NTRS)
Rodkey, R. Scott
Studies of a zwitterionic buffer formulated for cell electrophoresis were done using the McDonnell-Douglas Continuous Flow Electrophoresis System. Standard buffers were analyzed for their stability in the electrical field and the results showed that both buffers tested were inherently unstable. Further, titration studies showed that the standards buffers buffered poorly at the pH employed for electrophoresis. The zwitterionic buffer buffered well at its nominal pH and was shown to be stable in the electrical field. Comparative studies of the buffer with standard cell separation buffers using formalin fixed rabbit and goose red blood cells showed that the zwitterionic buffer gave better resolution of the fixed cells. Studies with viable hybridoma cells showed that buffer Q supported cell viability equal to Hank's Balanced Salt Solution and that hybridoma cells in different stages of the growth cycle demonstrated reproducible differences in electrophoretic mobility.
Fragment Analysis of Carbohydrates Following Capillary Electrophoresis
Hulce, D.; Li, F.; Li, X.; Liu, C.S.; Snyder-Leiby, T.
Depending on the macromolecule size and configuration, migration rates through capillary electrophoresis vary greatly. Internal size standards for capillary electrophoresis of the same macromolecule may not be readily available. The Macromolecule Tool in GeneMarker� aids with analysis of macromolecule fragments without an internal lane size standard. Methods included importing raw data files to the software and physically identifying reference peaks in the samples known to have the same size. The program uses this information to calibrate from one capillary to another. Characteristics of the aligned data (such as relative size, peak height, peak area, peak ratios) were exported in an excel sheet. Ninety six raw data files from 4 dye capillary electrophoresis were analyzed. Peak height, height ratio, area, area ratio, and relative sizes were determined for all samples. These values can be used to determine characteristics such as number and relative size of degradation products or other macromolecules, such as DNA binding carbohydrates commonly functioning in gene regulation.
Role of gravity in preparative electrophoresis
NASA Technical Reports Server (NTRS)
Bier, M.; Hinckley, J. O. N.; Smolka, A. J. K.; Binder, M. J.; Coxon, M.; Nee, T. W.; Scully, M. O.; Shih, H. S. T.; Snyder, R. S.
Electrophoresis has contributed significantly to the methodology of biological sciences, and shows the potential for large scale fractionation of a wide range of medically important substances, including living cells. Gravity plays an important role in the electrophoretic process, and hence the importance of the NASA effort to develop a zero-gravity separation facility as part of its shuttle program. The current state of art in electrophoresis is reviewed with particular emphasis on the role of gravity and the possible use of istachophoresis. This technique utilizes a discontinuous buffer system, and appears to be the only high resolution electrophoretic technique currently available for separation of living cells.
Electromembrane extraction: distribution or electrophoresis?
Seip, Knut Fredrik; Jensen, Henrik; S�nsteby, Marit Hovde; Gjelstad, Astrid; Pedersen-Bjergaard, Stig
This paper presents for the first time a phenomenological theoretical model for the time dependent distribution of analytes during electromembrane extraction (EME). The model was verified experimentally for a range of model drugs and peptides. Analytes were extracted from an acidified aqueous sample solution, through an organic supported liquid membrane (SLM), and into an acidified aqueous acceptor solution. Mass transfer was governed by an applied electric field across the SLM. A rapid depletion was seen in the sample during extractions, with a steady increase in the amount accumulated in the acceptor solution. This was in good accordance with the theoretical model. A deviation from the modeled behavior was seen for some of the peptides where trapping of analyte in the SLM was high. The results demonstrated for the first time that EME behaved like a distribution system, with voltage dependent distribution coefficients. In addition, electrokinetic migration was observed across the SLM, which added an electrophoretic component to the mass transfer. This improved theoretical understanding will be highly beneficial for future optimization and development of applications using EME. PMID:23255056
Acetic Acid Induces pH-Independent Cellular Energy Depletion in Salmonella enterica.
Tan, Sin Mei; Lee, Sui Mae; Dykes, Gary A
Weak organic acids are widely used as preservatives and disinfectants in the food industry. Despite their widespread use, the antimicrobial mode of action of organic acids is still not fully understood. This study investigated the effect of acetic acid on the cell membranes and cellular energy generation of four Salmonella strains. Using a nucleic acid/protein assay, it was established that acetic acid did not cause leakage of intracellular components from the strains. A scanning electron microscopy study further confirmed that membrane disruption was not the antimicrobial mode of action of acetic acid. Some elongated Salmonella cells observed in the micrographs indicated a possibility that acetic acid may inhibit DNA synthesis in the bacterial cells. Using an ATP assay, it was found that at a neutral pH, acetic acid caused cellular energy depletion with an ADP/ATP ratio in the range between 0.48 and 2.63 (p<0.05) that was apparent for the four Salmonella strains. We suggest that this effect was probably due solely to the action of undissociated acid molecules. The antimicrobial effect of acetic acid was better under acidic conditions (ADP/ATP ratio of 5.56�1.27; p<0.05), where the role of both pH and undissociated acid molecules can act together. We concluded that the inhibitory effect of acetic acid is not solely attributable to acidic pH but also to undissociated acid molecules. This finding has implication for the use of acetic acid as an antimicrobial against Salmonella on food products, such as chicken meat, which can buffer its pH. PMID:25562466
Validation of capillary electrophoresis method for determination of N-methylpyrrolidine in cefepime for injection.
Prasanna, S John; Sharma, Hemant Kr; Mukkanti, K; Kumar, V Jagadeesh; Raja, G; Sivakumaran, M
The present study relates to a new capillary electrophoresis method for the determination of N-methylpyrrolidine, an impurity considered to be toxic and also potential degradation impurity in cefepime hydrochloride drug substance. The newly developed capillary electrophoresis method for determining the content of N-methylpyrrolidine in cefepime for injection has been validated as per International Conference on Harmonization (ICH) guidelines to prove the selectivity, sensitivity, suitability, robustness, and ruggedness of the method. This simple, efficient, and rapid methodology may be used by pharmaceutical industry for routine analysis as well as during stability studies. The newly developed capillary electrophoresis method to determine the content of N-methylpyrrolidine in cefepime for injection requires 10 min for data acquisition, and uses an indirect UV photometry method to detect the analyte signal at 240 nm against the reference signal at 210 nm. The electrophoretic system is optimized to get stable base line, higher signal to noise ratio and peaks with narrow peak width. The method employs bare fused silica capillary with extended light path, effective length of capillary is 56 cm and inner diameter of capillary is 50 ?m, 5 mmole of imidazole buffer adjusted to pH 5.1 with 3 molar acetic acid solution is used as background electrolyte. The sample is introduced in hydrodynamic mode employing pressure of 50 mbar for 5 s, and the desired separation is achieved with constant applied voltage of 25 kV at ambient temperature (~25�C). PMID:21044414
Molecular Structure of Ethyl acetate
NSDL National Science Digital Library
Ethyl acetate is a colorless, volatile liquid with a mild and fragrant odor. It is used as solvent in chemistry laboratories but can also be found in many household products such as paints, coatings, and adhesives. The compound is also used in some extraction processes such as decaffeination or purification of antibiotics. It is present in both nail polish and removers. Some synthetic fruit essences may contain this and other esters. Etymologists like to use this solvent for insect collecting as the vapor kill the insect quickly and keep it soft for mounting.
[Antiovulatory action of chlormadinone acetate].
Pelissier, C; Blacker, C; Feinstein, M C; Cournot, A; Denis, C
Antiovulatory action of chlormadinone acetate (5 mg twice daily from day 7 to day 25) has been assessed in 6 healthy volunteers by daily determination of plasma FSH, LH, estradiol and progesterone. Hormonal profiles during the second treated cycle show that preovulatory gonadotropin surge is blunted and that no significant progesterone secretion occurs. Estradiol production is variable up to the middle of the cycle, and then homogeneously low normal. Menstrual cyclicity is respected and ovarian function is restored during the first cycle after treatment disruption. PMID:7511024
Identification of calcium-binding proteins associated with the human sperm plasma membrane
Soren Naaby-Hansen; Alan Diekman; Jagathpala Shetty; Charles J Flickinger; Anne Westbrook; John C Herr
BACKGROUND: The precise composition of the human sperm plasma membrane, the molecular interactions that define domain specific functions, and the regulation of membrane associated proteins during the capacitation process, still remain to be fully understood. Here, we investigated the repertoire of calcium-regulated proteins associated with the human sperm plasma membrane. METHODS: Surface specific radioiodination was combined with two-dimensional gel electrophoresis,
Study on dicarboxylic acids in aerosol samples with capillary electrophoresis.
Adler, Heidi; Sir�n, Heli
The research was performed to study the simultaneous detection of a homologous series of ? , ? -dicarboxylic acids (C2-C10), oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, and sebacic acids, with capillary electrophoresis using indirect UV detection. Good separation efficiency in 2,6-pyridinedicarboxylic acid as background electrolyte modified with myristyl trimethyl ammonium bromide was obtained. The dicarboxylic acids were ionised and separated within five minutes. For the study, authentic samples were collected onto dry cellulose membrane filters of a cascade impactor (12 stages) from outdoor spring aerosols in an urban area. Hot water and ultrasonication extraction methods were used to isolate the acids from membrane filters. Due to the low concentrations of acids in the aerosols, the extracts were concentrated with solid-phase extraction (SPE) before determination. The enrichment of the carboxylic acids was between 86 and 134% with sample pretreatment followed by 100-time increase by preparation of the sample to 50? ? L. Inaccuracy was optimised for all the sample processing steps. The aerosols contained dicarboxylic acids C2-C10. Then, mostly they contained C2, C5, and C10. Only one sample contained succinic acid. In the study, the concentrations of the acids in aerosols were lower than 10?ng/m(3). PMID:24729915
Study on Dicarboxylic Acids in Aerosol Samples with Capillary Electrophoresis
Adler, Heidi; Sir�n, Heli
The research was performed to study the simultaneous detection of a homologous series of ?, ?-dicarboxylic acids (C2�C10), oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, and sebacic acids, with capillary electrophoresis using indirect UV detection. Good separation efficiency in 2,6-pyridinedicarboxylic acid as background electrolyte modified with myristyl trimethyl ammonium bromide was obtained. The dicarboxylic acids were ionised and separated within five minutes. For the study, authentic samples were collected onto dry cellulose membrane filters of a cascade impactor (12 stages) from outdoor spring aerosols in an urban area. Hot water and ultrasonication extraction methods were used to isolate the acids from membrane filters. Due to the low concentrations of acids in the aerosols, the extracts were concentrated with solid-phase extraction (SPE) before determination. The enrichment of the carboxylic acids was between 86 and 134% with sample pretreatment followed by 100-time increase by preparation of the sample to 50??L. Inaccuracy was optimised for all the sample processing steps. The aerosols contained dicarboxylic acids C2�C10. Then, mostly they contained C2, C5, and C10. Only one sample contained succinic acid. In the study, the concentrations of the acids in aerosols were lower than 10?ng/m3. PMID:24729915
DNA's central importance in all biological systems dictates a wide variety of DNA-related research. or much of this research, the utilization of capillary electrophoresis (CE) can be of significant advantage. pen-tube CE yields excellent separations of DNA components, which can b...
A Simple Vertical Slab Gel Electrophoresis Apparatus.
ERIC Educational Resources Information Center
Carter, J. B.; And Others
Describes an inexpensive, easily constructed, and safe vertical slab gel kit used routinely for sodium dodecyl sulphate-polyacrylamide gel electrophoresis research and student experiments. Five kits are run from a single transformer. Because toxic solutions are used, students are given plastic gloves and closely supervised during laboratory�
Role of gravity in preparative electrophoresis
NASA Technical Reports Server (NTRS)
Bier, M.
The fundamental formulas of electrophoresis are derived microscopically and applied to the problem of isotachophoresis. A simple physical model of the isotachophoresis front is proposed. The front motion and structure are studied in the simplified case without convection, diffusion and non-electric external forces.
Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by alkaline gel electrophoresis.
The Genetic Science Learning Center: Gel Electrophoresis
NSDL National Science Digital Library
Gel Electrophoresis, designed and run by the University of Utah, is an interactive program that allows the student to learn and practice basic techniques that molecular biologists use every day. This program is an interactive animated procedure that allows the user to "see" DNA strands and instructs the student or user on the basics of DNA.
The repton model of gel electrophoresis
G. T. Barkema; M. E. J. Newman
We discuss the repton model of agarose gel electrophoresis of DNA. We review previous results, both analytic and numerical, as well as presenting a new numerical algorithm for the efficient simulation of the model, and suggesting a new approach to the model's analytic solution.
Using Gel Electrophoresis To Illustrate Protein Diversity and Isoelectric Point.
ERIC Educational Resources Information Center
Browning, Mark; Vanable, Joseph
Demonstrates the differences in protein structures by focusing on isoelectric point with an experiment that is observable under certain pH levels in gel electrophoresis. Explains the electrophoresis procedure and reports results of the experiments. (YDS)
Gel Electrophoresis on a Budget to Dye For
NSDL National Science Digital Library
Julie H. Yu
Gel electrophoresis is one of the most important tools used in molecular biology and has facilitated the entire field of genetic engineering by enabling the separation of nucleic acids and proteins. However, commercial electrophoresis kits can cost up to
Enzymatic production of glycerol acetate from glycerol.
Oh, Seokhyeon; Park, Chulhwan
In this study, we report the enzymatic production of glycerol acetate from glycerol and methyl acetate. Lipases are essential for the catalysis of this reaction. To find the optimum conditions for glycerol acetate production, sequential experiments were designed. Type of lipase, lipase concentration, molar ratio of reactants, reaction temperature and solvents were investigated for the optimum conversion of glycerol to glycerol acetate. As the result of lipase screening, Novozym 435 (Immobilized Candida antarctica lipase B) was turned out to be the optimal lipase for the reaction. Under the optimal conditions (2.5 g/L of Novozym 435, 1:40 molar ratio of glycerol to methyl acetate, 40 �C and tert-butanol as the solvent), glycerol acetate production was achieved in 95.00% conversion. PMID:25640720
A new procedure for the phosphorylation and assay of phosphoproteins is described. Proteins are solubilized from tissue samples, separated by polyacrylamide gel electrophoresis, transferred onto nitrocellulose membrane filters and the blotted polypeptides are phosphorylated with ...
Putative ABC Transporter Responsible for Acetic Acid Resistance in Acetobacter aceti
Nakano, Shigeru; Fukaya, Masahiro; Horinouchi, Sueharu
Two-dimensional gel electrophoretic analysis of the membrane fraction of Acetobacter aceti revealed the presence of several proteins that were produced in response to acetic acid. A 60-kDa protein, named AatA, which was mostly induced by acetic acid, was prepared; aatA was cloned on the basis of its NH2-terminal amino acid sequence. AatA, consisting of 591 amino acids and containing ATP-binding cassette (ABC) sequences and ABC signature sequences, belonged to the ABC transporter superfamily. The aatA mutation with an insertion of the neomycin resistance gene within the aatA coding region showed reduced resistance to acetic acid, formic acid, propionic acid, and lactic acid, whereas the aatA mutation exerted no effects on resistance to various drugs, growth at low pH (adjusted with HCl), assimilation of acetic acid, or resistance to citric acid. Introduction of plasmid pABC101 containing aatA under the control of the Escherichia coli lac promoter into the aatA mutant restored the defect in acetic acid resistance. In addition, pABC101 conferred acetic acid resistance on E. coli. These findings showed that AatA was a putative ABC transporter conferring acetic acid resistance on the host cell. Southern blot analysis and subsequent nucleotide sequencing predicted the presence of aatA orthologues in a variety of acetic acid bacteria belonging to the genera Acetobacter and Gluconacetobacter. The fermentation with A. aceti containing aatA on a multicopy plasmid resulted in an increase in the final yield of acetic acid. PMID:16391084
Nonwoven fabric supported poly(acrylonitrile-vinyl acetate) gel electrolyte for lithium ion battery use
Xiaoping Li; Mumin Rao; Youhao Liao; Weishan Li; Mengqing Xu
This paper reported on a new gel polymer electrolyte (GPE) based on polyethylene (PE) non-woven fabric supported poly(acrylonitrile-vinyl\\u000a acetate) (P(AN-VAc)\\/PE) membrane for lithium ion battery use. The preparation and performances of the P(AN-VAc)\\/PE membrane\\u000a and its GPE based on 1�M LiPF6 in dimethyl carbonate\\/diethylene carbonate\\/ethylene carbonate (1:1:1 in volume) were investigated with a comparison of the\\u000a unsupported P(AN-VAc) membrane. It
Acetate kinase: a triple-displacement enzyme.
Spector, L B
Facts relating to the mechanism of phosphoryl transfer by acetate kinase (ATP:acetate phosphotransferase, EC 22.214.171.124) are reviewed. They point to the existence of at least one experimentally established phosphoenzyme (E-P) intermediate on the reaction pathway. Sterically, the phosphoryl transfer occurs with a net inversion of the configuration of the phosphorus atom. These facts are best in accord with a triple-displacement mode of action for acetate kinase, with two E-P intermediates and three steric inversions on phosphorus. It follows that a second E-P for acetate kinase must exist. PMID:6248856
Contact dermatitis induced by glatiramer acetate.
Haltmeier, S; Yildiz, M; M�ller, S; Anliker, M D; Heinzerling, L
Glatiramer acetate (Copaxone(�)) is an immunomodulatory polypeptide used in patients with relapsing-remitting multiple sclerosis. It represents a safe treatment option with mild side effects. In this study, we look at a 39-year-old woman who received glatiramer acetate as subcutaneous injections for two months and developed contact dermatitis. The drug had to be stopped, and treatment with topical prednisone was initiated. Prick/scratch testing was negative but the lymphocyte transformation test was highly positive for glatiramer acetate. This is the first report on contact dermatitis induced by glatiramer acetate injections. The treatment consisted of local topical steroids and cessation of the drug. PMID:21729979
Warping of electrophoresis gels using generalisations of dynamic programming
Glasbey, Chris
Warping of electrophoresis gels using generalisations of dynamic programming Chris Glasbey a single track in a 1-D electrophoresis gel, such as the pulsed-field gel electrophoresis (PFGE) shown in Fig 1(a), with another track. Gel tracks need to be aligned with tracks in a reference database
3448 Electrophoresis 2012, 33, 34483457 James Uplinger1
Li, Jiali
DNA molecules indeed translocated through a 10 nm nanopore by PCR amplification and gel electrophoresis. We also3448 Electrophoresis 2012, 33, 34483457 James Uplinger1 Brian Thomas1 Ryan Rollings1 Daniel by bulk electrophoresis-based measure- ments [59] and they have also been evaluated theoretically [4, 10
Protein Electrophoresis in the Biology Classroom Using "Safe" Gels.
ERIC Educational Resources Information Center
Atkins, Thomas
Describes the use of electrophoresis in the high school utilizing two new gels that are easy to pour, do not require degassing, can be used on a horizontal gel electrophoresis, and are not neurotoxic or carcinogenic health hazards. Large diagrams and written instructions are used to present the protocol of setting up the electrophoresis. (PR)
ANALYSIS OF TWO-DIMENSIONAL ELECTROPHORESIS GEL IMAGES Lars Pedersen Informatics and Mathematical of proteomics. The subject is Analysis of Two-dimensional Electrophoresis Gel Images. This work was carried out analysis of two-dimensional gel electrophoresis (2DGE) images. 2DGE is the leading technique to separate
Analysis of Inorganic Polyphosphates by Capillary Gel Electrophoresis
Church, George M.
Analysis of Inorganic Polyphosphates by Capillary Gel Electrophoresis Andrew Lee and George M This paper describes the development of a method that uses capillary gel electrophoresis (CGE) to analyze mix)n, by capillary gel electrophoresis. Samples of condensed inorganic phosphate are typically mixtures of (Pi
Adali, Tulay
INDEPENDENT COMPONENT ANALYSIS OF SIMULATED 2D ELECTROPHORESIS GELS Nicolle Correat, Haleh Safavit differentially expressed pro- teins in simulated two-dimensional electrophoresis (2DE) gels us- ing spatial in the spatial domain. 1. INTRODUCTION Two-dimensional electrophoresis (2DE) gel has been widely used to separate
Chitosan hollow fiber membranes.
Modrzejewska, Zofia; Eckstein, Wojciech
Chitosan hollow fibers were produced by wet spinning, taking advantage of the unique rheological properties of highly viscous chitosan solutions in acetic acid. The mechanical and separation properties of hollow fibers were tested. The mechanical properties were determined by measuring tensile force, tensile stress, elongation, and initial elasticity module. The separation properties were specified by determining retention coefficients of particular blood components and determining cut-off of the membrane by the analysis of dextran molecular weight distribution in the feed and permeate using a technique of gel chromatography (GPC)-Shimadzu gel chromatograph. PMID:14691939
Positron scattering from vinyl acetate
NASA Astrophysics Data System (ADS)
Chiari, L.; Zecca, A.; Blanco, F.; Garc�a, G.; Brunger, M. J.
Using a Beer-Lambert attenuation approach, we report measured total cross sections (TCSs) for positron scattering from vinyl acetate (C4H6O2) in the incident positron energy range 0.15-50 eV. In addition, we also report an independent atom model with screening corrected additivity rule computation results for the TCSs, differential and integral elastic cross sections, the positronium formation cross section and inelastic integral cross sections. The energy range of these calculations is 1-1000 eV. While there is a reasonable qualitative correspondence between measurement and calculation for the TCSs, in terms of the energy dependence of those cross sections, the theory was found to be a factor of �2 larger in magnitude at the lower energies, even after the measured data were corrected for the forward angle scattering effect.
Differences in electrophoresis patterns between plasma albumins of the cockatiel (Nymphicus hollandicus) and the chicken (Gallus gallus domesticus).
Archer, F J; Battison, A L
Unique migration patterns for chicken and cockatiel albumins were detected when electrophoresis was performed using cellulose acetate and agarose gel support media. Cockatiel albumin migrated to a position equivalent to chicken alpha globulins, while the migration of cockatiel prealbumin was similar to that of chicken albumin. A chicken prealbumin band was not detected. Cockatiel and chicken albumins purified by affinity chromatography had similar migration patterns when electrophoresis was performed under denaturing conditions [sodium dodecyl sulphate (SDS) ] in 7% polyacrylamide gel (PAGE). The molecular weights of both albumins were similar, and were estimated to be approximately 66,000 Da when compared to known molecular weight markers. The different migration patterns were attributed to variations in conformation and surface charge distribution of albumin molecules between the two species. The experimental and clinical consequences of these findings are briefly discussed. PMID:18483951
Manufacturing Ethyl Acetate From Fermentation Ethanol
NASA Technical Reports Server (NTRS)
Rohatgi, Naresh K.; Ingham, John D.
Conceptual process uses dilute product of fermentation instead of concentrated ethanol. Low-concentration ethanol, extracted by vacuum from fermentation tank, and acetic acid constitutes feedstock for catalytic reaction. Product of reaction goes through steps that increases ethyl acetate content to 93 percent by weight. To conserve energy, heat exchangers recycle waste heat to preheat process streams at various points.
Biodegradable Plastics Based on Cellulose Acetate
Alexander Ach
It is generally known that secondary cellulose acetate (with 53 to 56% acetyl groups) is suitable for thermoplastic processing. With appropriate plasticizers a plastic material is obtained which excels in transparency and pleasant texture, and it is therefore often used for tool handles, combs, spectacle frames, and the like. In principle, cellulose acetate with such a degree of substitution is
Electrophoretic extraction of proteins from two-dimensional electrophoresis gel spots
Zhang, Jian-Shi (Shanghai, CN); Giometti, Carol S. (Glenview, IL); Tollaksen, Sandra L. (Montgomery, IL)
After two-dimensional electrophoresis of proteins or the like, resulting in a polyacrylamide gel slab having a pattern of protein gel spots thereon, an individual protein gel spot is cored out from the slab, to form a gel spot core which is placed in an extraction tube, with a dialysis membrane across the lower end of the tube. Replicate gel spots can be cored out from replicate gel slabs and placed in the extraction tube. Molten agarose gel is poured into the extraction tube where the agarose gel hardens to form an immobilizing gel, covering the gel spot cores. The upper end portion of the extraction tube is filled with a volume of buffer solution, and the upper end is closed by another dialysis membrane. Upper and lower bodies of a buffer solution are brought into contact with the upper and lower membranes and are provided with electrodes connected to the positive and negative terminals of a DC power supply, thereby producing an electrical current which flows through the upper membrane, the volume of buffer solution, the agarose, the gel spot cores and the lower membrane. The current causes the proteins to be extracted electrophoretically from the gel spot cores, so that the extracted proteins accumulate and are contained in the space between the agarose gel and the upper membrane. A high percentage extraction of proteins is achieved. The extracted proteins can be removed and subjected to partial digestion by trypsin or the like, followed by two-dimensional electrophoresis, resulting in a gel slab having a pattern of peptide gel spots which can be cored out and subjected to electrophoretic extraction to extract individual peptides.
Numerical simulation of electrophoresis separation processes
NASA Technical Reports Server (NTRS)
Ganjoo, D. K.; Tezduyar, T. E.
A new Petrov-Galerkin finite element formulation has been proposed for transient convection-diffusion problems. Most Petrov-Galerkin formulations take into account the spatial discretization, and the weighting functions so developed give satisfactory solutions for steady state problems. Though these schemes can be used for transient problems, there is scope for improvement. The schemes proposed here, which consider temporal as well as spatial discretization, provide improved solutions. Electrophoresis, which involves the motion of charged entities under the influence of an applied electric field, is governed by equations similiar to those encountered in fluid flow problems, i.e., transient convection-diffusion equations. Test problems are solved in electrophoresis and fluid flow. The results obtained are satisfactory. It is also expected that these schemes, suitably adapted, will improve the numerical solutions of the compressible Euler and the Navier-Stokes equations.
DNA electrophoresis in a nanofence array�
Park, Sung-Gyu; Olson, Daniel W.
We present the design and implementation of an oxidized silicon �nanofence array� for long DNA electrophoresis. The device consists of a periodic array of post-filled regions (the nanofences) alternating with empty channel regions. Even in this prototype version, the nanofence array provides the resolving power of a hexagonal nanopost array without requiring any direct-write nanopatterning steps such as electron-beam lithography. Through detailed single molecule investigations, we demonstrate that the origin of the resolving power of the nanofence array is not a reduction in band broadening, which might be expected from the theories for DNA electrophoresis in post arrays. Rather, the enhanced stretching of the hooked DNA by the uniform electric field between nanofences increases the efficiency of the collisions. PMID:22388662
Multiplexed fluorescence detector system for capillary electrophoresis
Yeung, E.S.; Taylor, J.A.
A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis. 14 figs.
Review Capillary electrophoresis-mass spectrometry
Jianyi Cai; Jack Henion
As an on-line separation method, capillary electrophoresis (CE)-mass spectrometry (MS) distinguishes analytes by both their differences in electrophoretic mobilities and structural information. CE-MS combines the advantages of CE and MS so that information on both high separation efficiency and molecular masses and\\/or fragmentation can be obtained in one analysis. During the past few years CE-MS has undergone significant development both
Capillary zone electrophoresis-mass spectrometer interface
D`Silva, A.
A device for providing equal electrical potential between two loci unconnected by solid or liquid electrical conductors is provided. The device comprises a first electrical conducting terminal, a second electrical conducting terminal connected to the first terminal by a rigid dielectric structure, and an electrically conducting gas contacting the first and second terminals. This device is particularly suitable for application in the electrospray ionization interface between a capillary zone electrophoresis apparatus and a mass spectrometer. 1 fig.
Method and apparatus for continuous electrophoresis
Watson, Jack S. (Knoxville, TN)
A method and apparatus for conducting continuous separation of substances by electrophoresis are disclosed. The process involves electrophoretic separation combined with couette flow in a thin volume defined by opposing surfaces. By alternating the polarity of the applied potential and producing reciprocating short rotations of at least one of the surfaces relative to the other, small increments of separation accumulate to cause substantial, useful segregation of electrophoretically separable components in a continuous flow system.
Microfabricated Chip Electrophoresis Technology for DNA Analysis
Feng Xu; Lihua Zhang; Mohammad Jabasini; Yoshinobu Baba
In this report, two microfabricated chip electrophoresis techniques and several application studies were tested for rapid and high-resolution separation of double-stranded (ds)DNA. In one technique, low-viscosity hydroxypropylmethylcellulose-50 (HPMC-50) matrix accompanied by polyhydroxy compounds, such as mannitol, glucose, and glycerol, showed higher resolving power than conventionally and singly used HPMC-50 matrix. The new matrix is easy to be hyphenated in the
Serum protein electrophoresis in 147 dogs
S. W. Tappin; S. S. Taylor; S. Tasker; S. J. Dodkin; K. Papasouliotis; K. F. Murphy
Reference intervals for serum protein electrophoresis (SPE) were created from a group of 75 clinically healthy dogs and compared with SPE results obtained from clinical cases presented to the University of Bristol over an eight-and-a-half-year period. A total of 147 dogs, in which SPE had been performed, had complete case records available and thus met the inclusion criteria. Signalment and
Multiplexed fluorescence detector system for capillary electrophoresis
Yeung, Edward S. (Ames, IA); Taylor, John A. (Nevada, IA)
A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis.
Multiplexed fluorescence detector system for capillary electrophoresis
Yeung, Edward S. (Ames, IA); Taylor, John A. (Nevada, IA)
A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis.
Capillary zone electrophoresis-mass spectrometer interface
D'Silva, Arthur (Ames, IA)
A device for providing equal electrical potential between two loci unconnected by solid or liquid electrical conducts is provided. The device comprises a first electrical conducting terminal, a second electrical conducting terminal connected to the first terminal by a rigid dielectric structure, and an electrically conducting gas contacting the first and second terminals. This device is particularly suitable for application in the electrospray ionization interface between a capillary zone electrophoresis apparatus and a mass spectrometer.
Extensions of Gel Electrophoresis with Proteins
NSDL National Science Digital Library
Mr. Brian McClain (Amos P. Godby High School)
This inquiry activity is intended to help familiarize students with the procedure of agarose electrophoresis and to make them aware of the types of proteins within tissue samples. This inquiry activity was developed by a K-12 science teacher in the American Physiological Society�?s 2006 Frontiers in Physiology Program. The NSES Standards addressed by this activity are current as of the year of development. For more information on the Frontiers in Physiology Program, please visit www.frontiersinphys.org.
Portable electrophoresis apparatus using minimum electrolyte
NASA Technical Reports Server (NTRS)
Stevens, M. R.; Vickers, J. M. (inventors)
An electrophoresis unit for use in conducting electrophoretic analysis of specimens is described. The unit includes a sealable container in which a substrate mounted specimen is suspended in an electrolytic vapor. A heating unit is employed to heat a supply of electrolyte to produce the vapor. The substrate is suspended within the container by being attached between a pair of clips which also serve as electrodes to which a direct current power source may be connected.
Determination of fosfomycin in pus by capillary zone electrophoresis.
Petsch, Martina; Mayer-Helm, Bernhard X; Sauermann, Robert; Joukhadar, Christian; Kenndler, Ernst
A method is described for the determination of fosfomycin in pus by capillary zone electrophoresis with reversed electroosmotic flow, and indirect UV absorbance detection. Sample pre-treatment is limited to removal of proteins and cell debris by adding the double volume of methanol, followed by vortexing for few seconds, and centrifugation at 15,000 x g for 2 min. The supernatant is directly injected into the instrument. Fosfomycin is separated from sample constituents with a background electrolyte at pH 7.25 (25 mM benzoate buffer with 0.5 mM hexadecyltrimethylammonium bromide added, adjusted to pH with tris(hydroxymethyl)-aminomethane (TRIS)). Separation is carried out in a capillary with 50 microm I.D., 64.5 cm total length, 56.0 cm to the detector, at 25 degrees C with -25 kV voltage applied. Due to the low absorbance of the analyte, indirect UV detection was performed at 254 nm using a bubble cell capillary. Sample was injected by pressure (450 mbar s). Repeatability for fosfomycin in spiked pus (from 8 or 10 consecutive injections of three different series at concentrations of 100 microg/mL of the antibiotic) was between 2.4 and 8.2% relative standard deviation (RSD). Accuracy (expressed as recovery of fosfomycin determined by three independent analysis at 10, 100 and 300 microg/mL fosfomycin added to plain pus) was between 75 and 102%. Intermediate reproducibility (n = 9 at three different days) was between 2 and 12% RSD. Limit of detection and limit of quantitation were 4.5 and 15 microg/mL, respectively. The concentration of fosfomycin in pus of patients treated with the antibiotic ranged up to 240 microg/mL. The concentration of other anionic pus constituents identified beside chloride (acetate, succinate, lactate, phosphate) ranged between 20 and 7800 microg/mL. PMID:16013598
Acetate in mixotrophic growth medium affects photosystem II in Chlamydomonas reinhardtii and protects against photoinhibition.
Roach, Thomas; Sedoud, Arezki; Krieger-Liszkay, Anja
Chlamydomonas reinhardtii is a photoautotrophic green alga, which can be grown mixotrophically in acetate-supplemented media (Tris-acetate-phosphate). We show that acetate has a direct effect on photosystem II (PSII). As a consequence, Tris-acetate-phosphate-grown mixotrophic C. reinhardtii cultures are less susceptible to photoinhibition than photoautotrophic cultures when subjected to high light. Spin-trapping electron paramagnetic resonance spectroscopy showed that thylakoids from mixotrophic C. reinhardtii produced less (1)O2 than those from photoautotrophic cultures. The same was observed in vivo by measuring DanePy oxalate fluorescence quenching. Photoinhibition can be induced by the production of (1)O2 originating from charge recombination events in photosystem II, which are governed by the midpoint potentials (Em) of the quinone electron acceptors. Thermoluminescence indicated that the Em of the primary quinone acceptor (QA/QA(-)) of mixotrophic cells was stabilised while the Em of the secondary quinone acceptor (QB/QB(-)) was destabilised, therefore favouring direct non-radiative charge recombination events that do not lead to (1)O2 production. Acetate treatment of photosystem II-enriched membrane fragments from spinach led to the same thermoluminescence shifts as observed in C. reinhardtii, showing that acetate exhibits a direct effect on photosystem II independent from the metabolic state of a cell. A change in the environment of the non-heme iron of acetate-treated photosystem II particles was detected by low temperature electron paramagnetic resonance spectroscopy. We hypothesise that acetate replaces the bicarbonate associated to the non-heme iron and changes the environment of QA and QB affecting photosystem II charge recombination events and photoinhibition. PMID:23791666
Ulipristal acetate in emergency contraception.
Goldstajn, Marina Sprem; Baldani, Dinka Pavici?; Skrgati?, Lana; Radakovi?, Branko; Vrbi?, Hrvoje; Cani?, Tomislav
Despite the widespread availability of highly effective methods of contraception, unintended pregnancy is common. Unplanned pregnancies have been linked to a range of health, social and economic consequences. Emergency contraception reduces risk of pregnancy after unprotected intercourse, and represents an opportunity to decrease number of unplanned pregnancies and abortions. Emergency contraception pills (ECP) prevent pregnancy by delaying or inhibiting ovulation, without interfering with post fertilization events. If pregnancy has already occurred, ECPs will not be effective, therefore ECPs are not abortificants. Ulipristal acetate (17alpha-acetoxy-11beta-(4N-N,N-dymethilaminophenyl)-19-norpregna--4,9-diene-3,20-dione) is the first drug that was specifically developed and licensed for use as an emergency contraceptive. It is an orally active, synthetic, selective progesterone modulator that acts by binding with high affinity to the human progesterone receptor where it has both antagonist and partial agonist effects. It is a new molecular entity and the first compound in a new pharmacological class defined by the pristal stem. Up on the superior clinical efficacy evidence, UPA has been quickly recognized as the most effective emergency contraceptive pill, and recently recommended as the first prescription choice for all women regardless of the age and timing after intercourse. This article provides literature review of UPA and its role in emergency contraception. PMID:24851646
Electrophoretic extraction of proteins from two-dimensional electrophoresis gel spots
Zhang, Jian-Shi; Giometti, C.S.; Tollaksen, S.L.
After two-dimensional electrophoresis of proteins or the like, resulting in a polyacrylamide gel slab having a pattern of protein gel spots thereon, an individual protein gel spot is cored out from the slab, to form a gel spot core which is placed in an extraction tube, with a dialysis membrane across the lower end of the tube. Replicate gel spots can be cored out from replicate gel slabs and placed in the extraction tube. Molten agarose gel is poured into the extraction tube where the agarose gel hardens to form an immobilizing gel, covering the gel spot cores. The upper end portion of the extraction tube is filled with a volume of buffer solution, and the upper end is closed by another dialysis membrane. Upper and lower bodies of a buffer solution are brought into contact with the upper and lower membranes and are provided with electrodes connected to the positive and negative terminals of a dc power supply, thereby producing an electrical current which flows through the upper membrane, the volume of buffer solution, the agarose, the gel spot cores and the lower membrane. The current causes the proteins to be extracted electrophoretically from the gel spot cores, so that the extracted proteins accumulate and are contained in the space between the agarose gel and the upper membrane. 8 figs.
21 CFR 582.5933 - Vitamin A acetate.
Code of Federal Regulations, 2013 CFR
...2013-04-01 2013-04-01 false Vitamin A acetate. 582.5933 Section 582...AS SAFE Nutrients and/or Dietary Supplements 1 � 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of...
21 CFR 582.5933 - Vitamin A acetate.
Code of Federal Regulations, 2011 CFR
...2011-04-01 2011-04-01 false Vitamin A acetate. 582.5933 Section 582...AS SAFE Nutrients and/or Dietary Supplements 1 � 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of...
21 CFR 582.5933 - Vitamin A acetate.
Code of Federal Regulations, 2012 CFR
...2012-04-01 2012-04-01 false Vitamin A acetate. 582.5933 Section 582...AS SAFE Nutrients and/or Dietary Supplements 1 � 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of...
21 CFR 582.5933 - Vitamin A acetate.
Code of Federal Regulations, 2010 CFR
...2010-04-01 2010-04-01 false Vitamin A acetate. 582.5933 Section 582...AS SAFE Nutrients and/or Dietary Supplements 1 � 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of...
21 CFR 582.5933 - Vitamin A acetate.
Code of Federal Regulations, 2014 CFR
...2014-04-01 2014-04-01 false Vitamin A acetate. 582.5933 Section 582...AS SAFE Nutrients and/or Dietary Supplements 1 � 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of...
21 CFR 522.1881 - Sterile prednisolone acetate aqueous suspension.
Code of Federal Regulations, 2010 CFR
... 2010-04-01 false Sterile prednisolone acetate aqueous suspension. 522...ANIMAL DRUGS � 522.1881 Sterile prednisolone acetate aqueous suspension. (a...suspension contains 25 milligrams of prednisolone acetate. (b) Sponsor . See...
A Single-Sample Method for Determination of Carbohydrate and Protein Contents Glycoprotein Bands Separated by Sodium Dodecyl Sulfate� Polyacrylamide Gel Electrophoresis
Ewa Zdebska; Jerzy Ko?cielak
A method is described for determination of carbohydrate and protein contents of glycoproteins separated by sodium dodecyl sulfate�polyacrylamide gel electrophoresis and then electroblotted onto polyvinylidene difluoride (PVDF) membranes. Blots were stained, and appropriate pieces of PVDF membranes were excised, destained, and subjected to sequential hydrolysis with 0.2 M trifluoroacetic acid (TFA) for 1 h at 80�C, then with 2 M
Isolation and partial characterization of Borrelia burgdorferi inner and outer membranes by using isopycnic centrifugation.
Bledsoe, H A; Carroll, J A; Whelchel, T R; Farmer, M A; Dorward, D W; Gherardini, F C
In order to characterize the protein composition of the outer membrane of Borrelia burgdorferi, we have isolated inner and outer membranes by using discontinuous sucrose density step gradients. Outer and inner membrane fractions isolated by this method contained less than 1 and 2%, respectively, of the total lactate dehydrogenase activity (soluble marker) in cell lysate. More importantly, the purified outer membranes contained less than 4% contamination by the C subunit of F1/F0 ATPase (inner membrane marker). Very little flagellin protein was present in the outer membrane sample. This indicated that the outer membranes were relatively free of contamination by cytoplasmic, inner membrane or flagellar components. The outer membrane fractions (rho = 1.19 g/cm3) contained 0.15 mg (dry weight) of protein per mg. Inner membrane samples (rho = 1.12 g/cm3) contained 0.60 mg (dry weight) of protein per mg. Freeze-fracture electron microscopy revealed that the outer membrane vesicles contained about 1,700 intramembranous particles per micron 2 while inner membrane densities for inner and outer membranes. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and nonequilibrium pH gel electrophoresis-SDS-PAGE analyses of inner and outer membrane samples revealed several proteins unique to the inner membrane and 20 proteins that localized specifically to the outer membrane. This analysis clearly shows that the inner and outer membranes isolated by this technique are unique structures. PMID:8002566
Isolation of Outer Membrane of Synechocystis sp. PCC 6803 and Its Proteomic Characterization
Fang Huang; Erik Hedman; Christiane Funk; Thomas Kieselbach; Wolfgang P. Schroder; Birgitta Norling
In this report, we describe a newly developed method for isolating outer membranes from Synechocystis sp. PCC 6803 cells. The purity of the outer membrane fraction was verified by immunoblot analysis using antibodies against membrane-specific marker proteins. We investigated the protein composition of the outer membrane using two- dimensional gel electrophoresis and matrix-assisted laser desorption\\/ionization time-of-flight mass spectrometry followed by
Viscosity of Mixtures of ?-Tocopherol Acetate + Mesitylene
NASA Astrophysics Data System (ADS)
Szwajczaka, El?bieta; Stagraczy?ski, Ryszard; Herba, Henryk; ?wiergielb, Jolanta; Jad?yn, Jan
The paper presents results of the share viscosity measurements performed as a function of temperature and concentration for mixtures of ?-tocopherol acetate (vitamine E acetate) and mesitylene, two liquids of essentially different viscosity (four order of magnitude difference at 280 K). The viscosity/ temperature dependence for pure ?-tocopherol acetate as well as for the mixtures studied can be well described with the Vogel-Fulcher-Tammann equation. The viscosities of the mixtures exhibit a strong negative deviation from the rule of additive dependence on concentration and for increasing temperature the maximum value of the deviation shows an exponential decreasing.
Sodium dodecyl sulphate-polyacrylamide denaturing gel electrophoresis and Western blotting techniques.
Blancher, Christine; Cormick, Rob Mc
The study of proteins, their expression and post-translational modification, is a key process in molecular biology. Immunoblotting is a well-established and powerful tool for the study of proteins, which continues to evolve as new reagents and apparatus are developed. This chapter describes in detail the process by which proteins are extracted from cells, quantified, fractionated using poly-acrylamide gel electrophoresis, transferred to a membrane, and assessed by immunoblotting. Variations in experimental technique, and new technologies available to the researcher, are also discussed. PMID:22674128
Microfluidic concentration of bacteria by on-chip electrophoresis
Puchberger-Enengl, Dietmar; Podszun, Susann; Heinz, Helene; Hermann, Carsten; Vulto, Paul; Urban, Gerald A.
In this contribution, we present a system for efficient preconcentration of pathogens without affecting their viability. Development of miniaturized molecular diagnostic kits requires concentration of the sample, molecule extraction, amplification, and detection. In consequence of low analyte concentrations in real-world samples, preconcentration is a critical step within this workflow. Bacteria and viruses exhibit a negative surface charge and thus can be electrophoretically captured from a continuous flow. The concept of phaseguides was applied to define gel membranes, which enable effective and reversible collection of the target species. E. coli of the strains XL1-blue and K12 were used to evaluate the performance of the device. By suppression of the electroosmotic flow both strains were captured with efficiencies of up to 99%. At a continuous flow of 15??l/min concentration factors of 50.17?�?2.23 and 47.36?�?1.72 were achieved in less than 27?min for XL1-blue and K12, respectively. These results indicate that free flow electrophoresis enables efficient concentration of bacteria and the presented device can contribute to rapid analyses of swab-derived samples. PMID:22207893
Membrane characteristics for biological blast overpressure testing using blast simulators.
Alphonse, Vanessa D; Siva Sai Sujith Sajja, Venkata; Kemper, Andrew R; Rizel, Dave V; Duma, Stefan M; VandeVord, Pamela J
Blast simulators often use passive-rupture membranes to generate shock waves similar to free-field blasts. The purpose of this study was to compare rupture patterns and pressure traces of three distinct membrane materials for biological and biomechanical blast studies. An Advanced Blast Simulator (ABS) located at the Center for Injury Biomechanics at Virginia Tech was used to test membrane characteristics. Acetate, Mylar, and aluminum sheets with different thicknesses were used to obtain pressures between 70?210 kPa. Static pressure was measured inside the tube at the test section using piezoelectric pressure sensors. Peak overpressure, positive duration, and positive impulse were calculated for each test. Rupture patterns and characteristic pressure traces were unique to each membrane type and thickness. Shock wave speed ranged between 1.2-1.8 Mach for static overpressures of 70?210 kPa. Acetate membranes fragmented sending pieces down the tube, but produced ideal (Friedlander) pressure traces. Mylar membranes bulged without fragmenting, but produced less-than-ideal pressure traces. Aluminum membranes did not fragment and produced ideal pressure traces. However, the cost of manufacturing and characterizing aluminum membranes should be considered during membrane selection. This study illustrates the advantages and disadvantages of using Mylar, acetate, and aluminum for passive rupture membranes for blast simulators. PMID:25405432
The pharmacology of nomegestrol acetate.
Ruan, Xiangyan; Seeger, Harald; Mueck, Alfred O
Nomegestrol acetate (NOMAC) is a 19-norprogesterone derivative with high biological activity at the progesterone receptor, a weak anti-androgenic effect, but with no binding to estrogen, glucocorticoid or mineralocorticoid receptors. At dosages of 1.5mg/day or more, NOMAC effectively suppresses gonadotropic activity and ovulation in women of reproductive age. Hemostasis, lipids and carbohydrate metabolism remain largely unchanged. In normal and cancerous human breast cells, NOMAC has shown favorable effects on estrogen metabolism. Like natural progesterone (but in contrast to some other synthetic progestogens), it does not appear stimulate the proliferation of cancerous breast cells. While there has been some experience of the use of NOMAC in combination with estrogens as a hormone replacement therapy, most of the data on the compound are reported in the context of its inclusion as a component of a new contraceptive pill comprising 2.5mg NOMAC combined with 1.5mg estradiol. Because of its strong endometrial efficacy, and due to its high antigonadotropic activity and long elimination half-life (about 50h), the contraceptive efficacy of the new pill is maintained even when dosages are missed. Furthermore, for the first time with a monophasic 24/4 regimen containing estradiol, cyclical stability can be achieved comparable with that obtained using pills containing ethinyl estradiol and progestogens like levonorgestrel or drospirenone. The addition of NOMAC to estradiol means that the beneficial effects of estrogen are not lost, which is of especial importance in relation to the cardiovascular system. On the basis both of its pharmacology and of studies performed during the development of the NOMAC/estradiol pill, involving some 4000 women in total, good long-term tolerability can be expected for NOMAC, although its safety profile is still to be fully ascertained, as the clinical endpoint studies are yet to be completed. PMID:22364709
The fluid mechanics of continuous flow electrophoresis
NASA Technical Reports Server (NTRS)
Saville, D. A.
The overall objective is to establish theoretically and confirm experimentally the ultimate capabilities of continuous flow electrophoresis chambers operating in an environment essentially free of particle sedimentation and buoyancy. The efforts are devoted to: (1) studying the effects of particle concentration on sample conductivity and dielectric constant. The dielectric constant and conductivity were identified as playing crucial roles in the behavior of the sample and on the resolving power and throughput of continuous flow devices; and (2) improving the extant mathematical models to predict flow fields and particle trajectories in continuous flow electrophoresis. A dielectric spectrometer was designed and built to measure the complex dielectric constant of a colloidal dispersion as a function of frequency between 500 Hz and 200 kHz. The real part of the signal can be related to the sample's conductivity and the imaginary part to its dielectric constant. Measurements of the dielectric constants of several different dispersions disclosed that the dielectric constants of dilute systems of the sort encountered in particle electrophoresis are much larger than would be expected based on the extant theory. Experiments were carried out to show that, in many cases, this behavior is due to the presence of a filamentary structure of small hairs on the particle surface. A technique for producing electrokinetically ideal synthetic latex particles by heat treating was developed. Given the ubiquitous nature of hairy surfaces with both cells and synthetic particles, it was deemed necessary to develop a theory to explain their behavior. A theory for electrophoretic mobility of hairy particles was developed. Finally, the extant computer programs for predicting the structure of electro-osmotically driven flows were extended to encompass flow channels with variable wall mobilities.
DNA electrophoresis on a flat surface.
Pernodet, N; Samuilov, V; Shin, K; Sokolov, J; Rafailovich, M H; Gersappe, D; Chu, B
We report a new approach for performing DNA electrophoresis. Using experimental studies and molecular dynamics simulations, we show that a perfectly flat silicon wafer, without any surface features, can be used to fractionate DNA in free solution. We determine that the ability of a flat surface to separate DNA molecules results from the local friction between the surface and the adsorbed DNA segments. We control this friction by coating the Si surface with silane monolayer films and show that it is possible to systematically change the size range of DNA that can be separated. PMID:11136069
Fluid mechanics of continuous flow electrophoresis
NASA Technical Reports Server (NTRS)
Saville, D. A.; Ostrach, S.
The following aspects of continuous flow electrophoresis were studied: (1) flow and temperature fields; (2) hydrodynamic stability; (3) separation efficiency, and (4) characteristics of wide gap chambers (the SPAR apparatus). Simplified mathematical models were developed so as to furnish a basis for understanding the phenomena and comparison of different chambers and operating conditions. Studies of the hydrodynamic stability disclosed that a wide gap chamber may be particularly sensitive to axial temperature variations which could be due to uneven heating or cooling. The mathematical model of the separation process includes effects due to the axial velocity, electro-osmotic cross flow and electrophoretic migration, all including the effects of temperature dependent properties.
Biotechnology Laboratory: Gel Electrophoresis of Dyes
NSDL National Science Digital Library
A portion of the Partnership for Plant Genomics Education, hosted by the University of California-Davis, this PDF presents a student activity where students will use agarose gel electrophoresis to separate several different dyes. The lab is described as a �??precursor to DNA separations�?� and thus provides an important step in the subject matter. The lab provides for students: detailed instructions, background information, and a quiz and group questions. Answers to the questions, and also the general objective of the lab, are provided for the instructor. Overall, the lab is introductory in nature and perfect for any science classroom.
Hybrid slab-microchannel gel electrophoresis system
Balch, Joseph W. (Livermore, CA); Carrano, Anthony V. (Livermore, CA); Davidson, James C. (Livermore, CA); Koo, Jackson C. (San Ramon, CA)
A hybrid slab-microchannel gel electrophoresis system. The hybrid system permits the fabrication of isolated microchannels for biomolecule separations without imposing the constraint of a totally sealed system. The hybrid system is reusable and ultimately much simpler and less costly to manufacture than a closed channel plate system. The hybrid system incorporates a microslab portion of the separation medium above the microchannels, thus at least substantially reducing the possibility of non-uniform field distribution and breakdown due to uncontrollable leakage. A microslab of the sieving matrix is built into the system by using plastic spacer materials and is used to uniformly couple the top plate with the bottom microchannel plate.
Microfabricated capillary array electrophoresis device and method
Simpson, Peter C. (Oakland, CA); Mathies, Richard A. (Moraga, CA); Woolley, Adam T. (Belmont, MA)
A capillary array electrophoresis (CAE) micro-plate with an array of separation channels connected to an array of sample reservoirs on the plate. The sample reservoirs are organized into one or more sample injectors. One or more waste reservoirs are provided to collect wastes from reservoirs in each of the sample injectors. Additionally, a cathode reservoir is also multiplexed with one or more separation channels. To complete the electrical path, an anode reservoir which is common to some or all separation channels is also provided on the micro-plate. Moreover, the channel layout keeps the distance from the anode to each of the cathodes approximately constant.
Microfabricated capillary array electrophoresis device and method
Simpson, Peter C.; Mathies, Richard A.; Woolley, Adam T.
A capillary array electrophoresis (CAE) micro-plate with an array of separation channels connected to an array of sample reservoirs on the plate. The sample reservoirs are organized into one or more sample injectors. One or more waste reservoirs are provided to collect wastes from reservoirs in each of the sample injectors. Additionally, a cathode reservoir is also multiplexed with one or more separation channels. To complete the electrical path, an anode reservoir which is common to some or all separation channels is also provided on the micro-plate. Moreover, the channel layout keeps the distance from the anode to each of the cathodes approximately constant.
Cytokine Analysis by Immunoaffinity Capillary Electrophoresis
Mendonca, Mark; Kalish, Heather
Immunoaffinity capillary electrophoresis (ICE) is a powerful tool used to detect and quantify target proteins of interest in complex biological fluids. The target analyte is captured and bound to antibodies immobilized onto the wall of a capillary, labeled in situ with a fluorescent dye, eluted and detected online using laser-induced fluorescence following electrophoretic separation. Here, we illustrate how to construct an immunoaffinity capillary and utilize it to run ICE in order to capture and quantify target cytokines and chemokines from a clinical sample. PMID:22976107
Fragrance material review on 4-methylbenzyl acetate.
McGinty, D; Letizia, C S; Api, A M
A toxicologic and dermatologic review of 4-methylbenzyl acetate when used as a fragrance ingredient is presented. 4-Methylbenzyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 4-methylbenzyl acetate were evaluated, then summarized, and includes: physical properties, skin irritation, skin sensitization, and elicitation data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22414643
A centrifugal method for the evaluation of polymer membranes for reverse osmosis
NASA Technical Reports Server (NTRS)
Hollahan, J. R.; Wydeven, T.; Mccullough, R. P.
A rapid and simple method employing the laboratory centrifuge shows promise for evaluation of membrane performance during reverse osmosis. Results are presented for cellulose acetate membranes for rejection of salt and urea dissolved solids. Implications of the study are to rapid screening of membrane performance, use in laboratories with limited facilities, and possible space waste water purification.
Distinct Effects of Sorbic Acid and Acetic Acid on the Electrophysiology and Metabolism of Bacillus subtilis
van Beilen, J. W. A.; Teixeira de Mattos, M. J.; Hellingwerf, K. J.
Sorbic acid and acetic acid are among the weak organic acid preservatives most commonly used to improve the microbiological stability of foods. They have similar pKa values, but sorbic acid is a far more potent preservative. Weak organic acids are most effective at low pH. Under these circumstances, they are assumed to diffuse across the membrane as neutral undissociated acids. We show here that the level of initial intracellular acidification depends on the concentration of undissociated acid and less on the nature of the acid. Recovery of the internal pH depends on the presence of an energy source, but acidification of the cytosol causes a decrease in glucose flux. Furthermore, sorbic acid is a more potent uncoupler of the membrane potential than acetic acid. Together these effects may also slow the rate of ATP synthesis significantly and may thus (partially) explain sorbic acid's effectiveness. PMID:25038097
Capillary electrophoresis for the detection of Fragile X expanded alleles.
Mao, Rong; Bayrak-Toydemir, Pinar; Lyon, Elaine
Capillary electrophoresis is an analytical technique that separates ions based on their electrophoresis mobility with the use of an applied voltage. Capillary electrophoresis is used most predominantly in nuclear acid fragment analysis as well as DNA sequencing because it gives faster results and provides high resolution separation. Here we describe an application using capillary electrophoreses for screening the Fragile X expanded alleles to demonstrate the application. PMID:22976108
Seperation of proteins using cetyltrimethylammonium bromide discontinuous gel electrophoresis
Robert E. Akins; Rocky S. Tuan
The gel electrophoresis system presented here allows the separation of proteins with the concomitant retention of detectable\\u000a native activities. The system, referred to as CAT gel electrophoresis. uses the detergent cetyltrimethylammonium bromide in\\u000a combination with a discontinuous gel matrix to resolve protein mixtures into discrete bands. Many proteins retain detectable\\u000a levels of native activity after CAT electrophoresis, and gel bands
Identification and characterization of Campylobacter jejuni outer membrane proteins.
Blaser, M J; Hopkins, J A; Berka, R M; Vasil, M L; Wang, W L
Outer membrane proteins from isolates of Campylobacter jejuni were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Sarcosinate-insoluble membrane preparations were outer membrane enriched based on increased ketodeoxyoctonate concentrations, the presence of surface-exposed 125I-labeled proteins that were hydrophobic, and similarity to membrane vesicle (bleb) sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles. Most isolates contained a single major band with molecular weight of 41,000 to 45,000. Profiles of C. jejuni and Campylobacter coli isolates were indistinguishable, but either could be easily differentiated from Campylobacter fetus and Campylobacter faecalis. The profiles were stable for strains under a variety of growth, incubation and passage conditions. We classified 110 isolates from patients with sporadic campylobacter enteritis into nine subtypes based on differences in outer membrane sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles. Two categories accounted for 76% of the isolates. Complete concordance was observed in subtypes of strains obtained from epidemiologically related cases. Thus, comparison of the major outer membrane proteins of C. jejuni is a useful technique for investigating the transmission of this organism and may provide a basis for immunological characterization of the outer membrane proteins. Images PMID:6618667
Bactericidal effect of ADP and acetic acid on Bacillus subtilis.
Asensi, V; Parra, F; Fierer, J; Valle, E; Bordallo, C; Rendueles, P; Gasc�n, S; Carton, J A; Maradona, J A; Arribas, J M
Bacillus subtilis is a ubiquitous soil bacterium used for measuring the beta-lysin activity and in other bioassays. We observed a complete bactericidal effect of ADP on B. subtilis at concentrations of 50-100 microM at pH values <5.5, which disappeared at pH values above 6. The effect was also found for acetic acid at concentrations >17.4 microM and similar pH values. ATP, adenosine, and HCl were not bactericidal. We used BCECF-AM, a pH-sensitive probe, and found that the killing of B. subtilis was due to a change in the intracellular pH caused by the passage across the cell membrane of these weak organic acids when incubated with B. subtilis at pH values near the pK. More experiments are needed to determine the biological meaning of these in vitro findings. PMID:8939804
Analysis of phenolic acids by non-aqueous capillary electrophoresis after electrokinetic supercharging.
Lu, Yuanqi; Breadmore, Michael C
Electrokinetic supercharging (EKS), a new and powerful on-line preconcentration method for capillary electrophoresis, was utilized in non-aqueous capillary electrophoresis (NACE) to enhance the sensitivity of phenolic acids. The buffer acidity and concentration, leader and terminator length and electrokinetic injection time were optimised, with the optimum conditions being: a background electrolyte of 40 mM Tris-acetic acid (pH 7.9), hydrodynamic injection of 50 mM ammonium chloride (22 s, 0.5 psi) as leader, electrokinetic injection of the sample (180 s, -10 kV), hydrodynamic injection of 20 mM CHES (32 s, 0.5 psi) as terminator, before application of the separation voltage (-25 kV). Under these conditions the sensitivity was enhanced between 1333 and 3440 times when compared to a normal hydrodynamic injection with the sample volume <3% of the capillary volume. Detection limits for the seven phenolic acids were in the range of 0.22-0.51 ng/mL and EKS was found to be 3.6-7.9 times more sensitive than large-volume sample stacking and anion selective exhaustive injection for the same seven phenolic acids. PMID:20934181
Determination of herbicides paraquat, glyphosate, and aminomethylphosphonic acid in marijuana samples by capillary electrophoresis.
Lanaro, Rafael; Costa, Jos� L; Cazenave, Silvia O S; Zanolli-Filho, Luiz A; Tavares, Marina F M; Chasin, Alice A M
In this work, two methods were developed to determine herbicides paraquat, glyphosate, and aminomethylphosphonic acid (AMPA) in marijuana samples by capillary electrophoresis. For paraquat analysis, sample was extracted with aqueous acetic acid solution and analyzed by capillary zone electrophoresis with direct UV detection. The running electrolyte was 50 mmol/L phosphate buffer (pH 2.50). For glyphosate and AMPA, indirect UV/VIS detection was used, as these substances do not present chromophoric groups. Samples were extracted with 5 mmol/L hydrochloric acid. The running electrolyte was 10 mmol/L gallic acid, 6 mmol/L TRIS, and 0.1 mmol/L CTAB (pH = 4.7). The methods presented good linearity, precision, accuracy, and recovery. Paraquat was detected in 12 samples (n = 130), ranging from 0.01 to 25.1 mg/g. Three samples were positive for glyphosate (0.15-0.75 mg/g), and one sample presented AMPA as well. Experimental studies are suggested to evaluate the risks of these concentrations to marijuana user. PMID:25413634
Protein fouling of surface-modified polymeric microfiltration membranes
Jeffrey Mueller; Robert H. Davis
The effects of varying morphology and surface chemistry on protein fouling of microfiltration membranes were investigated. In part I of the study, on the effects of varying morphology, results show that 0.2 ?m track-etched polycarbonate (PC) membranes internally foul, with external fouling becoming the dominant means of fouling only at later times. A 0.2 ?m cellulose acetate (CA) membrane showed
Association and release of the major intrinsic membrane glycoprotein from peripheral nerve myelin.
Poduslo, J F; Yao, J K
Hypo-osmotic homogenization of the endoneurium from the adult-rat sciatic nerve and subsequent evaluation of the 197 000 g aqueous supernatant by sodium dodecyl sulphate pore-gradient electrophoresis (SDS-p.g.e.) revealed a release of the major glycoprotein (P0) (29 000 Mr) from peripheral nerve myelin. Immunological verification of the presence of this asparagine-linked glycoprotein in the aqueous supernatant was obtained by immune overlay after SDS-p.g.e. and electrophoretic transfer to nitrocellulose using anti-P0 gamma-globulin followed by autoradiographic detection with 125I-protein A. A comparison of successive hypo- and iso-osmotic extractions of the endoneurium revealed that the hypo-osmotic extraction released increasing amounts of P0 into the supernatant fraction, whereas the iso-osmotic treatment revealed lower levels of P0 extracted from the myelin and lesser amounts with each successive extraction. Three successive hypo-osmotic extractions resulted in a 2.0-, 2.9-, and 9.5-fold increase in the amount of P0 released compared with the successive iso-osmotic extractions. Although these results suggest that this major myelin glycoprotein has properties similar to those of extrinsic membrane proteins, temperature-dependent phase-partitioning experiments with Triton X-114 revealed that this glycoprotein is recovered in the detergent-enriched lower phase. These results indicate that this major myelin glycoprotein is an amphipathic integral membrane protein with a distinct hydrophobic domain and yet has solubility characteristics typical of an extrinsic membrane protein. P0 labelled in vitro with [3H]mannose could be immunoprecipitated from the aqueous supernatant with anti-P0 gamma-globulin by centrifugation at 197000g without the addition of second antibody or protein A. Analysis of such an immune precipitate after incorporation in vitro with [14C]acetate to label endoneurial lipids revealed that all major endoneurial lipid classes contained radioactive label, as determined by fluorography after high-performance t.l.c. The mechanism of release of this intrinsic glycoprotein from the myelin membrane, therefore, involves the osmotic-dependent formation of mixed micelles or membrane vesicles with endogenous membrane lipids. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 6. Fig. 7. Fig. 8. Fig. 9. PMID:2408610
Acetate free biofiltration. Effects on peripheral blood monocyte activation and cytokine release.
Carozzi, S; Nasini, M G; Caviglia, P M; Schelotto, C; Santoni, O; Atti, M
Acetate free biofiltration (AFB), a new hemodiafiltration (HDF) technique characterized by a buffer free dialysate and postdilution infusion of a sterile HCO3 solution, was recently proposed as an alternative to HDF performed with acetate or bicarbonate dialysate. To evaluate the effects of dialysate buffer on immune cell activation, release of interleukin-1 (IL-1), tumor necrosis factor (TNF), prostaglandin E2 (PGE2), and leukotriene B4 (LTB4) from peripheral blood monocytes was studied in 12 uremic patients before and after HDF with polyacrylonitrile membranes (Filtral 12, Hospal Laboratories, Bologna, Italy) and consecutive dialysis with acetate, bicarbonate, and AFB. Data were correlated with the monocyte cytoplasmic concentration of Ca++, an index of early cell activation. Levels of bacterial endotoxins in the acetate, bicarbonate, buffer free dialysate, and infusate for AFB were also determined. Results showed that release of IL-1, PGE2, and LTB4, was greater after HDF with acetate than with bicarbonate; after bicarbonate dialysis, however, TNF production was significantly higher. On the other hand, after AFB, minimal production of these cytokines was seen and TNF, in particular, was undetectable. There was a direct correlation between release of cytokines in the monocytes and cytoplasmic Ca++ content. In the bicarbonate dialysate, detectable levels of bacterial endotoxins were found, whereas the acetate, buffer free dialysate, and infusate were endotoxin free. It was concluded that acetate dialysis directly activates peripheral blood monocytes to produce IL-1, PGE2, and LTB4, whereas bicarbonate induced TNF activation occurs through endotoxins. In AFB, which uses a buffer free dialysate and sterile bicarbonate infusion, monocyte activation is negligible. PMID:1313318
Gel Electrophoresis of Gold-DNA Nanoconjugates
Pellegrino, T.; Sperling, R. A.; Alivisatos, A. P.; Parak, W. J.
Gold-DNA conjugates were investigated in detail by a comprehensive gel electrophoresis study based on 1200 gels. A controlled number of single-stranded DNA of different length was attached specifically via thiol-Au bonds to phosphine-stabilized colloidal gold nanoparticles. Alternatively, the surface of the gold particles was saturated with single stranded DNA of different length either specifically via thiol-Au bonds or by nonspecific adsorption. From the experimentally determined electrophoretic mobilities, estimates for the effective diameters of the gold-DNA conjugates were derived by applying two different data treatment approaches. The first method is based on making a calibration curve for the relation between effective diameters and mobilities with gold nanoparticles of known diameter. The second method is based on Ferguson analysis which uses gold nanoparticles of known diameter as reference database. Our study shows that effective diameters derived from gel electrophoresis measurements are affected with a high error bar as the determined values strongly depend on the method of evaluation, though relative changes in size upon binding of molecules can be detected with high precision. Furthermore, in this study, the specific attachment of DNA via gold-thiol bonds to Au nanoparticles is compared to nonspecific adsorption of DNA. Also, the maximum number of DNA molecules that can be bound per particle was determined. PMID:18401452
Fractionation of mineral species by electrophoresis
NASA Astrophysics Data System (ADS)
Dunning, J. D.; Herren, B. J.; Tipps, R. W.; Snyder, R. S.
The fractionation of fine-grained aggregates into their major components is a problem in many scientific areas including earth and planetary science. Electrophoresis, the transport of electrically charged particles, immersed in a suspension medium, by a direct current field (Bier, 1959), was employed in this study as a means of separating simulated lunar soil into its constituent minerals. In these tests, conducted in a static analytical cylindrical microelectrophoresis apparatus, samples of simulated lunar soil and samples of pure mineral constituents were placed in the chamber; the electrophoretic mobilities of the lunar soil and the individual mineral constituents were measured. In most of the suspension buffers employed separability was indicated, on the basis of differences in mobility, for all the constituent mineral species except ilmenite and pyroxene, which were not efficiently separable in any of the buffers. Although only a few suspension media were employed, the success of this initial study suggests that electrophoresis may be an important mineral fractionation option in fine-grained aggregate processing.
Fractionation of mineral species by electrophoresis
NASA Technical Reports Server (NTRS)
Dunning, J. D.; Herren, B. J.; Tipps, R. W.; Snyder, R. S.
The fractionation of fine-grained aggregates into their major components is a problem in many scientific areas including earth and planetary science. Electrophoresis, the transport of electrically charged particles, immersed in a suspension medium, by a direct current field (Bier, 1959), was employed in this study as a means of separating simulated lunar soil into its constituent minerals. In these tests, conducted in a static analytical cylindrical microelectrophoresis apparatus, samples of simulated lunar soil and samples of pure mineral constituents were placed in the chamber; the electrophoretic mobilities of the lunar soil and the individual mineral constituents were measured. In most of the suspension buffers employed separability was indicated, on the basis of differences in mobility, for all the constituent mineral species except ilmenite and pyroxene, which were not efficiently separable in any of the buffers. Although only a few suspension media were employed, the success of this initial study suggests that electrophoresis may be an important mineral fractionation option in fine-grained aggregate processing.
Abnormal erythrocyte membrane protein pattern in severe megaloblastic anemia.
Ballas, S K
The erythrocyte membrane protein pattern of patients with megaloblastic anemia was determined by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. In severe megaloblastic anemia, secondary either to folic acid or vitamin B12 deficiency, the erythrocyte membrane protein pattern was grossly abnormal, lacking bands 1, 2 (spectrin), and 3 and having several diffuse, faster migrating bands. After adequate vitamin replacement therapy, the erythrocyte membrane protein pattern returned to normal. In mild megaloblastic anemia, secondary either to folic acid of vitamin B12 deficiency, and in severe iron deficiency anemia, the erythrocyte membrane protein pattern was normal. Erythrocyte membrane protein pattern of normal membranes did not change after mixing with abnormal membranes before polyacrylamide gel electrophoresis in sodium dodecyl sulfate. Protease activity extracted from membranes of megalocytes was not different from normal. These findings indicate that the erythrocyte membrane protein pattern is abnormal in severe megaloblastic anemia and that this abnormality is not secondary to increased activity of the endogenous erythrocyte membrane proteinase. Images PMID:659579
Genomic Expression Program Involving the Haa1p-Regulon in Saccharomyces cerevisiae Response to Acetic Acid
Becker, Jorg D.; S�-Correia, Isabel
Abstract The alterations occurring in yeast genomic expression during early response to acetic acid and the involvement of the transcription factor Haa1p in this transcriptional reprogramming are described in this study. Haa1p was found to regulate, directly or indirectly, the transcription of approximately 80% of the acetic acid-activated genes, suggesting that Haa1p is the main player in the control of yeast response to this weak acid. The genes identified in this work as being activated in response to acetic acid in a Haa1p-dependent manner include protein kinases, multidrug resistance transporters, proteins involved in lipid metabolism, in nucleic acid processing, and proteins of unknown function. Among these genes, the expression of SAP30 and HRK1 provided the strongest protective effect toward acetic acid. SAP30 encode a subunit of a histone deacetylase complex and HRK1 encode a protein kinase belonging to a family of protein kinases dedicated to the regulation of plasma membrane transporters activity. The deletion of the HRK1 gene was found to lead to the increase of the accumulation of labeled acetic acid into acid-stressed yeast cells, suggesting that the role of both HAA1 and HRK1 in providing protection against acetic acid is, at least partially, related with their involvement in the reduction of intracellular acetate concentration. PMID:20955010
Nanofiltration of rhodium tris(triphenylphosphine) catalyst in ethyl acetate solution
NASA Astrophysics Data System (ADS)
Shaharun, Maizatul S.; Mustafa, Ahmad K.; Taha, Mohd F.
Solvent resistant nanofiltration (SRNF) using polymer membranes has recently received enhanced attention due to the search for cleaner and more energy-efficient technologies. The large size of the rhodium tris(triphenylphosphine) [HRh(CO)(PPh3)3] catalyst (>400 Da) - relative to other components of the hydroformylation reaction provides the opportunity for a membrane separation based on retention of the catalyst species while permeating the solvent. The compatibility of the solvent-polyimide membrane (DuraMem{trade mark, serif} 200 and DuraMem{trade mark, serif} 500) combinations was assessed in terms of the membrane stability in solvent plus non-zero solvent flux at 2.0 MPa. Good HRh(CO)(PPh3)3 rejection (>0.95) and solvent fluxes of 9.9 L/m2?h1 at 2.0 MPa were obtained in the catalyst-ethyl acetate-DuraMem 500 system. The effect of pressure and catalyst concentration on the solvent flux and catalyst rejection was conducted on the catalyst-ethyl acetate-membrane systems. Increasing pressure substantially improved both solvent flux and catalyst rejection, while increasing catalyst concentration was found to be beneficial in terms of substantial increases in catalyst rejection without significantly affecting solvent flux.
Membrane Extraction for Detoxification of Biomass Hydrolysates
Grzenia, D. L.; Schell, D. J.; Wickramasinghe, S. R.
Membrane extraction was used for the removal of sulfuric acid, acetic acid, 5-hydroxymethyl furfural and furfural from corn stover hydrolyzed with dilute sulfuric acid. Microporous polypropylene hollow fiber membranes were used. The organic extractant consisted of 15% Alamine 336 in: octanol, a 50:50 mixture of oleyl alcohol:octanol or oleyl alcohol. Rapid removal of sulfuric acid, 5-hydroxymethyl and furfural was observed. The rate of acetic acid removal decreased as the pH of the hydrolysate increased. Regeneration of the organic extractant was achieved by back extraction into an aqueous phase containing NaOH and ethanol. A cleaning protocol consisting of flushing the hydrolysate compartment with NaOH and the organic phase compartment with pure organic phase enabled regeneration and reuse of the module. Ethanol yields from hydrolysates detoxified by membrane extraction using 15% Alamine 336 in oleyl alcohol were about 10% higher than those from hydrolysates detoxified using ammonium hydroxide treatment.
Chia, Pei Zhi Cheryl
Membrane trafficking depends on transport vesicles and carriers docking and fusing with the target organelle for the delivery of cargo. Membrane tethers and small guanosine triphosphatases (GTPases) mediate the docking of transport vesicles/carriers to enhance the efficiency of the subsequent SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor)-mediated fusion event with the target membrane bilayer. Different classes of membrane tethers and their specific intracellular location throughout the endomembrane system are now well defined. Recent biochemical and structural studies have led to a deeper understanding of the mechanism by which membrane tethers mediate docking of membrane carriers as well as an appreciation of the role of tethers in coordinating the correct SNARE complex and in regulating the organization of membrane compartments. This review will summarize the properties and roles of membrane tethers of both secretory and endocytic systems. PMID:25343031
NSDL National Science Digital Library
Gary McCallister
While not organic in nature, quick-"growing" artificial membranes can be a profound visual aid when teaching students about cellular processes and the chemical nature of membranes. Students are often intrigued when they see biological and chemical concept
Radiation effects on bovine taste bud membranes
Shatzman, A.R.; Mossman, K.L.
In order to investigate the mechanisms of radiation-induced taste loss, the effects of radiation on preparations of enriched bovine taste bud membranes were studied. Taste buds containing circumvallate papilae, and surrounding control epithelial tissues devoid of taste buds, were obtained from steers and given radiation doses of 0-7000 cGy (rad). Tissue fractions were isolated into membrane-enriched and heterogeneous components using differential and sucrose gradient centrifugation of tissue homogenates. The yield of membranes, as measured by protein content in the buoyant membrane-enriched fractions, was reduced in quantity with increasing radiation dose. The relation between radiation dose and membrane quantity in membrane-enriched fractions could be fit by a simple exponential model with taste bud-derived membranes twice as radiosensitive as membranes from control epithelial tissue. Binding of sucrose, sodium, and acetate and fluoride stimulation of adenylate cyclase were nearly identical in both irradiated and nonirradiated intact membranes. Radiation had no effect on fractions of heterogeneous components. While it is not clear what changes are occurring in enriched taste cell membranes, damage to membranes may play an important role in the taste loss observed in patients following radiotherapy.
SHORT COMMUNICATION Evaluation of non-ionic and zwitterionic detergents as membrane protein solubilizers
Paris-Sud XI, Université de
1 SHORT COMMUNICATION Evaluation of non-ionic and zwitterionic detergents as membrane protein plantes, place Viala, 34060 Montpellier cedex 1, France Running title: detergents for 2D electrophoresis;2 SUMMARY The solubilizing power of various nonionic and zwitterionic detergents as membrane protein
Alterations in outer membrane proteins of Pseudomonas aeruginosa associated with selective resistance to quinolones.
Daikos, G L; Lolans, V T; Jackson, G G
Electrophoresis of outer membrane proteins in three ciprofloxacin-resistant strains of Pseudomonas aeruginosa isolated during therapy and their in vitro revertants indicated that diminution or loss of a 31- to 32-kilodalton outer membrane protein correlated with resistance in two of the three isolates. Resistance was unstable and caused no cross-resistance with other antibiotics. Images PMID:3134852
Precise, fast, and flexible determination of protein interactions by affinity capillary electrophoresis: part 3: anions.
Xu, Yuanhong; Redweik, Sabine; El-Hady, Deia Abd; Albishri, Hassan M; Preu, Lutz; W�tzig, Hermann
The binding of physiologically anionic species or negatively charged drug molecules to proteins is of great importance in biochemistry and medicine. Since affinity capillary electrophoresis (ACE) has already proven to be a suitable analytical tool to study the influence of ions on proteins, this technique was applied here for comprehensively studying the influence of various anions on proteins of BSA, ?-lactoglobulin, ovalbumin, myoglobin, and lysozyme. The analysis was performed using different selected anions of succinate, glutamate, phosphate, acetate, nitrate, iodide, thiocyanate, and pharmaceuticals (salicylic acid, aspirin, and ibuprofen) that exist in the anionic form at physiological pH 7.4. Due to the excellent repeatability and precision of the ACE measurements, not necessarily strong but significant influences of the anions on the proteins were found in many cases. Different influences in the observed bindings indicated change of charge, mass, or conformational changes of the proteins due to the binding with the studied anions. Combining the mobility-shift and pre-equilibrium ACE modes, rapidity and reversibility of the protein-anion bindings were discussed. Further, circular dichroism has been used as an orthogonal approach to characterize the interactions between the studied proteins and anions to confirm the ACE results. Since phosphate and various anions from amino acids and small organic acids such as succinate or acetate are present in very high concentrations in the cellular environment, even weak influences are certainly relevant as well. PMID:24436007
Nonaqueous capillary electrophoresis equipped with amperometric detection for analysis of chlorinated phenolic compounds.
Luong, J H; Hilmi, A; Nguyen, A L
Nonaqueous capillary electrophoresis (NACE) equipped with amperometric detection has been developed for separation and detection of an 11-member model mixture of chlorinated phenolic compounds. With triacetyl-beta-cyclodextrin (TACD) as a novel selectivity selector, acetonitrile proved to be an excellent solvent for this water-insoluble cyclodextrin derivative. Resolution of the analytes was achieved by using an optimized acetonitrile medium consisting of 500 mM acetic acid, 10 mM sodium acetate, 12 mM TACD and 50 mM tetrabutylammonium perchlorate. Separation of analytes was attributed to differential electrostatic and/or inductive interactions of the analytes with the TACD/TBA+ complex and charged tetrabutylammonium phases. A simple end-column amperometric detector (Pt vs. Ag/AgCl, poised at +1.6 V) in conjunction with NACE was used to analyze chlorophenols. Amperometric detection of such target compounds in acetonitrile-based media offers high sensitivity and alleviates electrode fouling compared to aqueous buffers. The detection limits obtained, ranging from 30 nM to 500 nM, are 3-8-fold lower than those obtained with aqueous buffers. PMID:10669300
Golgi Enrichment and Proteomic Analysis of Developing Pinus radiata Xylem by Free-Flow Electrophoresis
Macdonald, Lucy J.; Adams, Paul D.; Petzold, Christopher J.; Strabala, Timothy J.; Wagner, Armin; Heazlewood, Joshua L.
Our understanding of the contribution of Golgi proteins to cell wall and wood formation in any woody plant species is limited. Currently, little Golgi proteomics data exists for wood-forming tissues. In this study, we attempted to address this issue by generating and analyzing Golgi-enriched membrane preparations from developing xylem of compression wood from the conifer Pinus radiata. Developing xylem samples from 3-year-old pine trees were harvested for this purpose at a time of active growth and subjected to a combination of density centrifugation followed by free flow electrophoresis, a surface charge separation technique used in the enrichment of Golgi membranes. This combination of techniques was successful in achieving an approximately 200-fold increase in the activity of the Golgi marker galactan synthase and represents a significant improvement for proteomic analyses of the Golgi from conifers. A total of thirty known Golgi proteins were identified by mass spectrometry including glycosyltransferases from gene families involved in glucomannan and glucuronoxylan biosynthesis. The free flow electrophoresis fractions of enriched Golgi were highly abundant in structural proteins (actin and tubulin) indicating a role for the cytoskeleton during compression wood formation. The mass spectrometry proteomics data associated with this study have been deposited to the ProteomeXchange with identifier PXD000557. PMID:24416096
Modification of gel architecture and TBE/TAE buffer composition to minimize heating during agarose gel electrophoresis.
Sanderson, Brian A; Araki, Naoko; Lilley, Jennifer L; Guerrero, Gilberto; Lewis, L Kevin
Agarose gel electrophoresis of DNA and RNA is routinely performed using buffers containing either Tris, acetate, and EDTA (TAE) or Tris, borate, and EDTA (TBE). Gels are run at a low, constant voltage (?10 V/cm) to minimize current and asymmetric heating effects, which can induce band artifacts and poor resolution. In this study, alterations of gel structure and conductive media composition were analyzed to identify factors causing higher electrical currents during horizontal slab gel electrophoresis. Current was reduced when thinner gels and smaller chamber buffer volumes were used, but was not influenced by agarose concentration or the presence of ethidium bromide. Current was strongly dependent on the amount and type of EDTA used and on the concentrations of the major acid-base components of each buffer. Interestingly, resolution and the mobilities of circular versus linear plasmid DNAs were also affected by the chemical form and amount of EDTA. With appropriate modifications to gel structure and buffer constituents, electrophoresis could be performed at high voltages (20-25 V/cm), reducing run times by up to 3-fold. The most striking improvements were observed with small DNAs and RNAs (10-100 bp): high voltages and short run times produced sharper bands and higher resolution. PMID:24637158
Recovering/concentrating of hemicellulosic sugars and acetic acid by nanofiltration and reverse osmosis from prehydrolysis liquor of kraft based hardwood dissolving pulp process.
Ahsan, Laboni; Jahan, M Sarwar; Ni, Yonghao
This work investigated the feasibility of recovering and concentrating sugars and acetic acid (HAc) from prehydrolysis liquor (PHL) of the kraft-based dissolving pulp process prior to fermentation of hemicellulosic sugars, by the combination of activated carbon adsorption, nanofiltration (NF) and reverse osmosis (RO) processes. To reduce the fouling PHL was subjected to adsorption on activated carbon, then the treated PHL (TPHL) passed through a nanofiltration (NF DK) membrane to retain the sugars, and the permeate of acetic acid rich solution was passed through a reverse osmosis membrane (RO SG). It was found that for NF process sugars were concentrated from 48 to 227g/L at a volume reduction factor (VRF) of 5 while 80 to 90% of acetic acid was permeated. For the reverse osmosis process, 68% of acetic acid retention was achieved at pH 4.3 and 500 psi pressure and the HAc concentration increased from 10 to 50g/L. PMID:24434701
Acetic acid production from food wastes using yeast and acetic acid bacteria micro-aerobic fermentation.
Li, Yang; He, Dongwei; Niu, Dongjie; Zhao, Youcai
In this study, yeast and acetic acid bacteria strains were adopted to enhance the ethanol-type fermentation resulting to a volatile fatty acids yield of 30.22�g/L, and improve acetic acid production to 25.88�g/L, with food wastes as substrate. In contrast, only 12.81�g/L acetic acid can be obtained in the absence of strains. The parameters such as pH, oxidation reduction potential and volatile fatty acids were tested and the microbial diversity of different strains and activity of hydrolytic ferment were investigated to reveal the mechanism. The optimum pH and oxidation reduction potential for the acetic acid production were determined to be at 3.0-3.5 and -500�mV, respectively. Yeast can convert organic matters into ethanol, which is used by acetic acid bacteria to convert the organic wastes into acetic acid. The acetic acid thus obtained from food wastes micro-aerobic fermentation liquid could be extracted by distillation to get high-pure acetic acid. PMID:25416587
Tested Demonstrations: Buffer Capacity of Various Acetic Acid-Sodium Acetate Systems: A Lecture Experiment.
ERIC Educational Resources Information Center
Donahue, Craig J.; Panek, Mary G.
Background information and procedures are provided for a lecture experiment which uses indicators to illustrate the concept of differing buffer capacities by titrating acetic acid/sodium acetate buffers with 1.0 molar hydrochloric acid and 1.0 molar sodium hydroxide. A table with data used to plot the titration curve is included. (JN)
Acetylation of Starch with Vinyl Acetate in Imidazolium Ionic Liquids and Characterization of Acetate Distribution
Technology Transfer Automated Retrieval System (TEKTRAN)
Starch was acetylated with vinyl acetate in different 1-butyl-3-methylimidazolium (BMIM) salts as solvent in effort to produce starches with different acetylation patterns. Overall degree of substitution was much higher for basic anions such as acetate and dicyanimide (dca) than for neutral anions ...
Inexpensive and Safe DNA Gel Electrophoresis Using Household Materials
ERIC Educational Resources Information Center
Ens, S.; Olson, A. B.; Dudley, C.; Ross, N. D., III; Siddiqi, A. A.; Umoh, K. M.; Schneegurt, M. A.
Gel electrophoresis is the single most important molecular biology technique and it is central to life sciences research, but it is often too expensive for the secondary science classroom or homeschoolers. A simple safe low-cost procedure is described here that uses household materials to construct and run DNA gel electrophoresis. Plastic�
Gel Electrophoresis on a Budget to Dye for
ERIC Educational Resources Information Center
Yu, Julie H.
Gel electrophoresis is one of the most important tools used in molecular biology and has facilitated the entire field of genetic engineering by enabling the separation of nucleic acids and proteins. However, commercial electrophoresis kits can cost up to $800 for each setup, which is cost prohibitive for most classroom budgets. This article�
A mammalian acetate switch regulates stress erythropoiesis
Xu, Min; Nagati, Jason S.; Xie, Jian; Li, Jiwen; Walters, Holly; Moon, Young-Ah; Gerard, Robert D.; Huang, Chou-Long; Comerford, Sarah A.; Hammer, Robert E.; Horton, Jay D.; Chen, Rui; Garcia, Joseph A.
Endocrine erythropoietin (Epo), which is synthesized in the kidney or liver of adult mammals, controls erythrocyte production and is regulated by the stress-responsive transcription factor Hypoxia Inducible Factor 2 (HIF-2). We previously reported that the lysine acetyltransferase Cbp is required for HIF-2? acetylation and efficient HIF-2 dependent Epo induction during hypoxia. We now show these processes require acetate-dependent acetyl CoA synthetase 2 (Acss2). In Hep3B hepatoma cells and in Epo-generating organs of hypoxic or acutely anemic mice, acetate levels increase and Acss2 is required for HIF-2? acetylation, Cbp/HIF-2? complex formation and recruitment to the Epo enhancer, and efficient Epo induction. In acutely anemic mice, acetate supplementation augments stress erythropoiesis in an Acss2-dependent manner. In acquired and genetic chronic anemia mouse models, acetate supplementation also increases Epo expression and resting hematocrits. Thus, a mammalian stress-responsive acetate switch controls HIF-2 signaling and Epo induction during pathophysiological states marked by tissue hypoxia. PMID:25108527
Novel absorption detection techniques for capillary electrophoresis
Xue, Y.
Capillary electrophoresis (CE) has emerged as one of the most versatile separation methods. However, efficient separation is not sufficient unless coupled to adequate detection. The narrow inner diameter (I.D.) of the capillary column raises a big challenge to detection methods. For UV-vis absorption detection, the concentration sensitivity is only at the {mu}M level. Most commercial CE instruments are equipped with incoherent UV-vis lamps. Low-brightness, instability and inefficient coupling of the light source with the capillary limit the further improvement of UV-vis absorption detection in CE. The goals of this research have been to show the utility of laser-based absorption detection. The approaches involve: on-column double-beam laser absorption detection and its application to the detection of small ions and proteins, and absorption detection with the bubble-shaped flow cell.
Microfabricated capillary array electrophoresis DNA analysis systems.
Medintz, I L; Paegel, B M; Mathies, R A
Microfabricated "laboratory-on-a-chip" systems are revolutionizing all aspects of genetic analysis. The development of capillary array electrophoresis (CAE) microchannel plate devices makes possible the performance of 96 or more high-speed separations in parallel on a single wafer-scale device. The fluorescently labeled DNA samples are detected within the microchannels with a novel four-color rotary confocal fluorescence scanner. The capabilities of this system for genotyping are demonstrated through multiplex separations of short tandem repeat and hereditary haemochromatosis allele-specific amplicons. Furthermore, with newly developed folded channel designs that maintain high resolution, these CAE microplate systems are used to perform 96 high-quality DNA sequencing separations in parallel to approximately 500 bases per capillary in less than 30 min. These densely packed microfabricated device technologies will facilitate the even more rapid collection of vast amounts of genetic data in the future. PMID:11521873
Hybrid slab-microchannel gel electrophoresis system
Balch, J.W.; Carrano, A.V.; Davidson, J.C.; Koo, J.C.
A hybrid slab-microchannel gel electrophoresis system is described. The hybrid system permits the fabrication of isolated microchannels for biomolecule separations without imposing the constraint of a totally sealed system. The hybrid system is reusable and ultimately much simpler and less costly to manufacture than a closed channel plate system. The hybrid system incorporates a microslab portion of the separation medium above the microchannels, thus at least substantially reducing the possibility of non-uniform field distribution and breakdown due to uncontrollable leakage. A microslab of the sieving matrix is built into the system by using plastic spacer materials and is used to uniformly couple the top plate with the bottom microchannel plate. 4 figs.
Combined electrophoresis-electrospray interface and method
Smith, Richard D. [Richland, WA; Udseth, Harold R. [Richland, WA; Olivares, Jose A. [Los Alamos, NM
A system and method for analyzing molecular constituents of a composition sample includes: forming a solution of the sample, separating the solution by capillary electrophoresis into an eluent of constituents longitudinally separated according to their relative electrophoretic mobilities, electrospraying the eluent to form a charged spray in which the molecular constituents have a temporal distribution; and detecting or collecting the separated constituents in accordance with the temporal distribution in the spray. A first high-voltage (e.g., 5-100 KVDC) is applied to the solution. The spray is charged by applying a second high voltage (e.g., .+-.2-8 KVDC) between the eluent at the capillary exit and a cathode spaced in front of the exit. A complete electrical circuit is formed by a conductor which directly contacts the eluent at the capillary exit, or by conduction through a sheath electrode discharged in an annular sheath flow about the capillary exit.
DNA gel electrophoresis: the reptation model(s).
Slater, Gary W
DNA gel electrophoresis has been the most important experimental tool to separate DNA fragments for several decades. The introduction of PFGE in the 1980s and capillary gel electrophoresis in the 1990s made it possible to study, map and sequence entire genomes. Explaining how very large DNA molecules move in a gel and why PFGE is needed to separate them has been an active field of research ever since the launch of the journal Electrophoresis. This article presents a personal and historical overview of the development of the theory of gel electrophoresis, focusing on the reptation model, the band broadening mechanisms, and finally the factors that limit the read length and the resolution of electrophoresis-based sequencing systems. I conclude with a short discussion of some of the questions that remain unanswered. PMID:19517509
Two-dimensional Gel Electrophoresis (2DE)
NASA Astrophysics Data System (ADS)
K?odzi?ska, Ewa; Buszewski, Bogus?aw
The chemical compounds, which are present in the environment, increasingly cause bad effects on health. The most serious effects are tumors and various mutations at the cellular level. Such compounds, from the analytical point of view, can serve the function of biomarkers, constituting measurable changes in the organism's cells and biochemical processes occurring therein. The challenge of the twenty-first century is therefore searching for effective and reliable methods of identification of biomarkers as well as understanding bodily functions, which occur in living organisms at the molecular level. The irreplaceable tool for these examinations is proteomics, which includes both quality and quantity analysis of proteins composition, and also makes it possible to learn their functions and expressions. The success of proteomics examinations lies in the usage of innovative analytical techniques, such as electromigration technique, two-dimensional electrophoresis in polyacrylamide gel (2D PAGE), liquid chromatography, together with high resolution mass spectrometry and bio-informatical data analysis. Proteomics joins together a number of techniques used for analysis of hundreds or thousands of proteins. Its main task is not the examination of proteins inside the particular tissue but searching for the differences in the proteins' profile between bad and healthy tissues. These differences can tell us a lot regarding the cause of the sickness as well as its consequences. For instance, using the proteomics analysis it is possible to find relatively fast new biomarkers of tumor diseases, which in the future will be used for both screening and foreseeing the course of illness. In this chapter we focus on two-dimensional electrophoresis because as it seems, it may be of enormous importance when searching for biomarkers of cancer diseases.
Effect of lead on erythrocyte membranes.
Fukumoto, K; Karai, I; Horiguchi, S
The effect of blood lead on erythrocyte membrane proteins was studied in 28 workers from a scrap lead refining factory and in 18 controls working in railway construction. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of the polypeptides in the erythrocyte membrane showed that bands 3 and 4.1 had significantly decreased while bands 2.3, 6, and 7 had significantly increased in the lead workers compared with the controls. For the lead workers, the correlation coefficients between blood lead and bands 2.3 and 3 were r = 0.545 (p less than 0.01) and r = -0.51 (p less than 0.01) respectively. These results suggest that the decrease in erythrocyte membrane permeability results from a decrease in the membrane transfer protein responsible for band 3. PMID:6830722
Relaxometry, luminescence measurements, electrophoresis, and animal biodistribution of lanthanide(III) complexes of some polyaza macrocyclic acetates containing pyridine
Kim, W.D.; Sherry, A.D. [Univ. of Texas, Dallas, Richardson, TX (United States); Kiefer, G.E.; McMillan, K. [Dow Chemical Co., Freeport, TX (United States); Maton, F.; Muller, R.N. [Univ. of Mons-Hainault (Belgium)
Four Gd{sup 3+} complexes [Gd(BP2A){sup +}, Gd(PC2A){sup +}, Gd(PCTA){sup 0}, and Gd(BPO4A){sup {minus}}] with polyazamacrocyclic ligands that contain a pyridine moiety were prepared and examined for possible use as MRI contrast enhancement agents. The authors estimated the number of inner sphere water molecules (q{sub Gd}) for the Gd{sup 3+} complexes from the values of q found for the Tb{sup 3+} and/or Eu{sup 3+} complexes by luminescence lifetime measurements. It was estimated that q{sub Gd} = 3.5, 3.3, 2.4, and 0.2 for Gd(BP2A){sup +}, Gd(PC2A){sup +}, Gd(PCTA){sup 0}, and Gd(BPO4A){sup {minus}}, respectively. The inner sphere relaxivities (r{sub 1,inner}) of these tetraaza macrocyclic complexes were higher than that of Gd(DOTA){sup {minus}} [i.e. 6.79 for Gd(BP2A){sup +}, 6.21 for Gd(PC2A){sup +}, and 4.60 for Gd(PCTA){sup 0} mM{sup {minus}1}s{sup {minus}1} at 40 MHz and 25{degrees}C], but the normalized relaxivities per q{sub Gd} (1.94, 1.88, and 1.92 mM{sup {minus}1}s{sup {minus}1}, respectively) were comparable to that of Gd(DOTA){sup {minus}}. A quantitative treatment of the NMRD profiles based on Solomon-Bloembergen-Morgan theory, using the NMRD profile of Gd(BPO4A){sup {minus}} to correct for an outer sphere contribution, showed that the complexes exhibit characteristics similar to that of Gd(DOTA){sup {minus}} but with shorter electronic relaxation times. Tissue biodistribution results using radioactive {sup 153}Sm and {sup 159}Gd complexes in rats indicate that the cationic [{sup 153}Sm-(BP2A){sup +} and {sup 153}Sm(PC2A){sup +}] complexes accumulate preferably in the bone tissue while the neutral [{sup 153}Sm-(PCTA){sup 0}] and anionic [{sup 153}Sm(BPO4A){sup {minus}}] complexes appear to have renal clearances similar to those of other low molecular weight contrast agents [i.e. Gd(DTPA){sup 2{minus}} and Gd(DOTA){sup {minus}}].
Multiple forms with glucose 6-phosphate dehydrogenase activity in Musca domestica L. as revealed by electrophoresis on cellulose acetate gel.
Cima, L; Malacrida, A; Gasperi, G; Sacchi, L; Grigolo, A
Single newly emerged males of Musca domestica, WHO strain, usually show five electrophoretic bands of glucose 6-phosphate dehydrogenase (G6PD) activity. Of these five molecular forms, designated with Roman numerals in order from the origin, we have considered the first three: these have been characterized with respect to their substrate and coenzyme specificity and to their sensitivity to some sulfhydryl inhibitors. The data show band III to be G6P specific, nicotinamide adenine dinucleotide phosphate dependent and to be a type I enzyme according to Kamada and Hori's classification. Bands I and II, on the other hand, show wide substrate specificity and low sensitivity to the sulfhydryl inhibitors assayed. In addition, in the absence of an exogenous substrate and in the presence of nicotinamide adenine dinucleotide as a coenzyme, fairly weak bands, which can be ascribed to the so called "nothing dehydrogenase" effect, are seen in the position I and II. Nevertheless, the data reported do not allow a clear definition of the enzymatic type corresponding to bands I and II of G6PD activity. PMID:31398
Electropermeabilization of the cell membrane.
Teissie, Justin
Membrane electropermeabilization is the observation that the permeability of a cell membrane can be transiently increased when a micro-millisecond external electric field pulse is applied on a cell suspension or on a tissue. Applicative aspects for the transfer of foreign molecules (macromolecules) into the cytoplasm are routinely used. But only a limited knowledge about what is really occurring in the cell and its membranes at the molecular levels is available. This chapter is a critical attempt to report the present state of the art and to point out some of the still open problems. The experimental facts associated to membrane electropermeabilization are firstly reported. They are valid on biological and model systems. Secondly, soft matter approaches give access to the bioelectrochemical description of the thermodynamical constraints supporting the destabilization of simplified models of the biological membrane. It is indeed described as a thin dielectric leaflet, where a molecular transport takes place by electrophoresis and then diffusion. This na�ve approach is due to the lack of details on the structural aspects affecting the living systems as shown in a third part. Membranes are part of the cell machinery. The critical property of cells as being an open system from the thermodynamical point of view is almost never present. Computer simulations are now contributing to our knowledge on electropermeabilization. The last part of this chapter is a (very) critical report of all the efforts that have been performed. The final conclusion remains that we still do not know all the details on the reversible structural and dynamical alterations of the cell membrane (and cytoplasm) supporting its electropermeabilization. We have a long way in basic and translational researches to reach a pertinent description. PMID:24510809
DNA sequencing using fluorescence background electroblotting membrane
Caldwell, K.D.; Chu, T.J.; Pitt, W.G.
A method for the multiplex sequencing on DNA is disclosed which comprises the electroblotting or specific base terminated DNA fragments, which have been resolved by gel electrophoresis, onto the surface of a neutral non-aromatic polymeric microporous membrane exhibiting low background fluorescence which has been surface modified to contain amino groups. Polypropylene membranes are preferably and the introduction of amino groups is accomplished by subjecting the membrane to radio or microwave frequency plasma discharge in the presence of an aminating agent, preferably ammonia. The membrane, containing physically adsorbed DNA fragments on its surface after the electroblotting, is then treated with crosslinking means such as UV radiation or a glutaraldehyde spray to chemically bind the DNA fragments to the membrane through amino groups contained on the surface. The DNA fragments chemically bound to the membrane are subjected to hybridization probing with a tagged probe specific to the sequence of the DNA fragments. The tagging may be by either fluorophores or radioisotopes. The tagged probes hybridized to the target DNA fragments are detected and read by laser induced fluorescence detection or autoradiograms. The use of aminated low fluorescent background membranes allows the use of fluorescent detection and reading even when the available amount of DNA to be sequenced is small. The DNA bound to the membranes may be reprobed numerous times. No Drawings
NSDL National Science Digital Library
Jack D. Thatcher (Lewisburg; West Virginia School of Osteopathic Medicine REV)
This Teaching Resource provides three animated lessons that describe the storage and utilization of energy across plasma membranes. The �Na,K ATPase� animation explains how these pumps establish the electrochemical gradient that stores energy across plasma membranes. The �ATP synthesizing complexes� animation shows how these complexes transfer energy from the inner mitochondrial membrane to adenosine triphosphate (ATP). The �action potential� lesson explains how charged membranes are used to propagate signals along the axons of neurons. These animations serve as valuable resources for any collegiate-level course that describes these important factors. Courses that might employ them include introductory biology, biochemistry, biophysics, cell biology, pharmacology, and physiology.
Process for the preparation of vinyl acetate
Tustin, Gerald Charles (Kingsport, TN); Zoeller, Joseph Robert (Kingsport, TN); Depew, Leslie Sharon (Kingsport, TN)
This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85.degree. and 200.degree. C. and removing the reaction products from the contact zone.
Process for the preparation of vinyl acetate
Tustin, G.C.; Zoeller, J.R.; Depew, L.S.
This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85 and 200 C and removing the reaction products from the contact zone.
Treatment of Pedophilia with Leuprolide Acetate
Nancy Raymond; Bean Robinson; Chris Kraft; Barry Rittberg; Eli Coleman
To date, the literature on the treatment of individuals who have committed sexual offenses has focused primarily on psychotherapeutic interventions and the use of antiandrogens. Recently case reports and small series supporting the efficacy of other psychiatric medication, such as serotonin reuptake inhibitors, have been published. Only a few publications have looked at the efficacy of leuprolide acetate, an LH-RH
Corrosion of stainless steel during acetate production
Qi, J.S.; Lester, G.C. [Occidental Chemical Corp. Technology Center, Grand Island, NY (United States)
Corrosion of types 304, 304L, 316, and 316L stainless steel (SS) during the esterification of acetic acid and alcohol or glycol ether was investigated. The catalyst for this reaction, sulfuric acid or para-toluene sulfonic acid (PTSA), was shown to cause more corrosion on reactor equipment than CH{sub 3}COOH under the process conditions commonly practiced in industry. The corrosive action of the catalyst occurred only in the presence of water. Thus, for the batch processes, corrosion occurred mostly during the initial stage of esterification, where water produced by the reaction created an aqueous environment. After water was distilled off, the corrosion rate declined to a negligible value. The corrosion inhibitor copper sulfate, often used in industrial acetate processes, was found to work well for a low-temperature process (< 95 C) such as in production of butyl acetate, but it accelerated corrosion in the glycol ether acetate processes where temperatures were > 108 C. Process conditions that imparted low corrosion rates were determined.
Heat Bonding of Irradiated Ethylene Vinyl Acetate
NASA Technical Reports Server (NTRS)
Slack, D. H.
Reliable method now available for joining parts of this difficult-tobond material. Heating fixture encircles ethylene vinyl acetate multiplesocket part, providing heat to it and to tubes inserted in it. Fixtures specially designed to match parts to be bonded. Tube-and-socket bonds made with this technique subjected to tensile tests. Bond strengths of 50 percent that of base material obtained consistently.
Extended length microchannels for high density high throughput electrophoresis systems
Davidson, James C. (Livermore, CA); Balch, Joseph W. (Livermore, CA)
High throughput electrophoresis systems which provide extended well-to-read distances on smaller substrates, thus compacting the overall systems. The electrophoresis systems utilize a high density array of microchannels for electrophoresis analysis with extended read lengths. The microchannel geometry can be used individually or in conjunction to increase the effective length of a separation channel while minimally impacting the packing density of channels. One embodiment uses sinusoidal microchannels, while another embodiment uses plural microchannels interconnected by a via. The extended channel systems can be applied to virtually any type of channel confined chromatography.
A novel approach to pseudopodia proteomics: excimer laser etching, two-dimensional difference gel electrophoresis, and confocal imaging
Mimae, Takahiro; Ito, Akihiko; Hagiyama, Man; Nakanishi, Jun; Hosokawa, Yoichiroh; Okada, Morihito; Murakami, Yoshinori; Kondo, Tadashi
Pseudopodia are actin-rich ventral cellular protrusions shown to facilitate the migration and metastasis of tumor cells. Here, we present a novel approach to perform pseudopodia proteomics. Tumor cells growing on porous membranes extend pseudopodia into the membrane pores. In our method, cell bodies are removed by horizontal ablation at the basal cell surface with the excimer laser while pseudopodia are left in the membrane pores. For protein expression profiling, whole cell and pseudopodia proteins are extracted with a lysis buffer, labeled with highly sensitive fluorescent dyes, and separated by two-dimensional gel electrophoresis. Proteins with unique expression patterns in pseudopodia are identified by mass spectrometry. The effects of the identified proteins on pseudopodia formation are evaluated by measuring the pseudopodia length in cancer cells with genetically modified expression of target proteins using confocal imaging. This protocol allows global identification of pseudopodia proteins and evaluation of their functional significance in pseudopodia formation within one month. PMID:25309719
Polyethylene-supported polyvinylidene fluoride-cellulose acetate butyrate blended polymer electrolyte for lithium ion battery
NASA Astrophysics Data System (ADS)
Liu, Jiansheng; Li, Weishan; Zuo, Xiaoxi; Liu, Shengqi; Li, Zhao
The polyethylene (PE)-supported polymer membranes based on the blended polyvinylidene fluoride (PVDF) and cellulose acetate butyrate (CAB) are prepared for gel polymer electrolyte (GPE) of lithium ion battery. The performances of the prepared membranes and the resulting GPEs are investigated by scanning electron microscopy, electrochemical impedance spectroscopy, linear potential sweep, and charge-discharge test. The effect of the ratio of PVDF to CAB on the performance of the prepared membranes is considered. It is found that the GPE based on the blended polymer with PVDF:CAB = 2:1 (in weight) has the largest ionic conductivity (2.48 � 10-3 S cm-1) and shows good compatibility with anode and cathode of lithium ion battery. The LiCoO2/graphite battery using this GPE exhibits superior cyclic stability at room temperature, storage performance at elevated temperature, and rate performance.
Fragrance material review on 3-phenyl-3-buten-1-yl acetate.
McGinty, D; Letizia, C S; Api, A M
A toxicologic and dermatologic review of 3-phenyl-3-buten-1-yl acetate when used as a fragrance ingredient is presented. 3-Phenyl-3-buten-1-yl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 3-phenyl-3-buten-1-yl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, and skin sensitization data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22402309
Fragrance material review on 1,1-dimethyl-2-phenylethyl acetate.
McGinty, D; Letizia, C S; Api, A M
A toxicologic and dermatologic review of 1,1-dimethyl-2-phenylethyl acetate when used as a fragrance ingredient is presented. 1,1-Dimethyl-2-phenylethyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an Aryl Alkyl Alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to 1,1-dimethyl-2-phenylethyl acetate and is not intended as a stand-alone document. Available data were evaluated, then summarized, and includes: physical properties; acute toxicity; skin irritation; mucous membrane (eye) irritation; skin sensitization; elicitation; and toxicokinetics data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22445843
Fragrance material review on 1,3-dimethyl-3-phenylbutyl acetate.
McGinty, D; Letizia, C S; Api, A M
A toxicologic and dermatologic review of 1,3-dimethyl-3-phenylbutyl acetate when used as a fragrance ingredient is presented. 1,3-Dimethyl-3-phenylbutyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1 to 4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 1,3-dimethyl-3-phenylbutyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, phototoxicity, and photoallergy data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22406562
The microwave spectrum of n-hexyl acetate and structural aspects of n-alkyl acetates
NASA Astrophysics Data System (ADS)
Attig, T.; Kannengie�er, R.; Kleiner, I.; Stahl, W.
The microwave spectrum of n-hexyl acetate was recorded in the range of 10-13.5 GHz using the Aachen MB-FTMW spectrometer. The rotational constants of the most abundant conformer were determined to be A = 3.3591100(32) GHz, B = 0.39596553(53) GHz, and C = 0.36999804(31) GHz. Quantum chemical calculations for specific conformers were carried out at the MP2/6-311++G(d,p) level. The programs XIAM and BELGI were used to analyze the internal rotation of the acetyl methyl group. The observed conformer of n-hexyl acetate was compared to the lowest energy conformers of n-butyl acetate and n-pentyl acetate.
Phenyl Acetate Preparation from Phenol and Acetic Acid: Reassessment of a Common Textbook Misconception.
ERIC Educational Resources Information Center
Hocking, M. B.
Reassesses a common textbook misconception that "...phenols cannot be esterified directly." Results of experiments are discussed and data tables provided of an effective method for the direct preparation of phenyl acetate. (CS)
Capillary electrophoresis for total glycosaminoglycan analysis.
Ucakturk, Ebru; Cai, Chao; Li, Lingyun; Li, Guoyun; Zhang, Fuming; Linhardt, Robert J
A capillary zone electrophoresis-laser-induced fluorescence detection (CZE-LIF) method was developed for the simultaneous analysis of disaccharides derived from heparan sulfate, chondroitin sulfate/dermatan sulfate, hyaluronan, and keratan sulfate. Glycosaminoglycans (GAGs) were first depolymerized with the mixture of GAG lyases (heparinase I, II, III and chondroitinase ABC and chondroitinase AC II) and GAG endohydrolase (keratinase II) and the resulting disaccharides were derivatized by reductive amination with 2-aminoacridone. Nineteen fluorescently labeled disaccharides were separated using 50 mM phosphate buffer (pH 3.3) under reversed polarity at 25 kV. Using these conditions, all the disaccharides examined were baseline separated in less then 25 min. This CZE-LIF method gave good reproducibility for both migration time (?1.03% for intraday and ?4.4% for interday) and the peak area values (?5.6% for intra- and ?8.69% for interday). This CZE-LIF method was used for profiling and quantification of GAG derivative disaccharides in bovine cornea. The results show that the current CZE-LIF method offers fast, simple, sensitive, reproducible determination of disaccharides derived from total GAGs in a single run. PMID:24817364
Strongly nonlinear waves in capillary electrophoresis
NASA Astrophysics Data System (ADS)
Chen, Zhen; Ghosal, Sandip
In capillary electrophoresis, sample ions migrate along a microcapillary filled with a background electrolyte under the influence of an applied electric field. If the sample concentration is sufficiently high, the electrical conductivity in the sample zone could differ significantly from the background. Under such conditions, the local migration velocity of sample ions becomes concentration-dependent, resulting in a nonlinear wave that exhibits shocklike features. If the nonlinearity is weak, the sample concentration profile, under certain simplifying assumptions, can be shown to obey Burgers� equation [Ghosal and Chen, Bull. Math. Biol.BMTBAP0092-824010.1007/s11538-010-9527-2 72, 2047 (2010)], which has an exact analytical solution for arbitrary initial condition. In this paper, we use a numerical method to study the problem in the more general case where the sample concentration is not small in comparison to the concentration of background ions. In the case of low concentrations, the numerical results agree with the weakly nonlinear theory presented earlier, but at high concentrations, the wave evolves in a way that is qualitatively different.
Denaturation and electrophoresis of RNA with glyoxal.
Rio, Donald C
This protocol is used to denature and separate large mRNA molecules (0.5-10 kb) on agarose gels by electrophoretic size fractionation. Glyoxal (also called diformyl or ethanedial), the agent responsible for maintaining denaturation in this protocol, contains two carbonyl groups that react to form a cyclic ring structure with the imino and amino groups of guanine. It can also react with the amino groups of adenine and cytidine. When RNA is denatured in the presence of glyoxal, this covalent adduct prevents normal base pairing and maintains the RNA in a denatured state in agarose gels. Once formed, these adducts are stable at room temperature at pH <7.0; thus, there is no need to add glyoxal to the gel or to the gel buffers to maintain the RNA in the denatured state. Because the fully denatured RNA migrates through agarose gels according to its molecular mass, this method can be used to accurately size mRNA molecules. Following electrophoresis and reversal of glyoxalation, the RNA can be detected using a northern hybridization procedure. PMID:25646499
Integrated polymerase chain reaction/electrophoresis instrument
Andresen, Brian D. (Livermore, CA)
A new approach and instrument for field identification of micro-organisms and DNA fragments using a small and disposable device containing integrated polymerase chain reaction (PCR) enzymatic reaction wells, attached capillary electrophoresis (CE) channels, detectors, and read-out all on/in a small hand-held package. The analysis instrument may be made inexpensively, for example, of plastic, and thus is disposable, which minimizes cross contamination and the potential for false positive identification between samples. In addition, it is designed for multiple users with individual applications. The integrated PCR/CE is manufactured by the PCR well and CE channels are "stamped" into plastic depressions where conductive coatings are made in the wells and ends of the CE microchannels to carry voltage and current to heat the PCR reaction mixtures and simultaneously draw DNA bands up the CE channels. Light is transmitted through the instrument at appropriate points and detects PCR bands and identifies DNA fragments by size (retention time) and quantifies each by the amount of light generated as each phototransistor positioned below each CE channel detects a passing band. The instrument is so compact that at least 100 PCR/CE reactions/analyses can be performed easily on one detection device.
Injector-concentrator electrodes for microchannel electrophoresis
Swierkowski, Stefan P.
An input port geometry, with injector-concentrator electrodes, for planar microchannel array for electrophoresis. This input port geometry enables efficient extraction and injection of the DNA sample from a single input port. The geometry, which utilizes injector-concentrator electrodes, allows simultaneous concentration, in different channels, of the sample into a longitudinally narrow strip just before releasing it for a run with enhanced injection spatial resolution, and time resolution. Optional multiple electrodes, at a different bias than the concentrator electrodes, may be used to discriminate against sample impurity ions. Electrode passivation can be utilized to prevent electrolysis. An additional electrode in or on the input hole can better define the initial loading. The injector-concentrator electrodes are positioned so that they cross the drift channel in a narrow strip at the bond plane between the top and bottom plates of the instrument and are located close to the inlet hole. The optional sample purification electrodes are located at a greater distance from the input hole than the injector-concentrate electrodes.
Contact charge electrophoresis: experiment and theory.
Drews, Aaron M; Cartier, Charles A; Bishop, Kyle J M
Contact charge electrophoresis (CCEP) uses steady electric fields to drive the continuous, oscillatory motion of conductive particles and droplets between two or more electrodes. These rapid oscillations can be rectified to direct the motion of objects within microfluidic environments using low-power, dc voltage. Here, we compare high precision experimental measurements of CCEP within a microfluidic system to equally detailed theoretical predictions on the motion of a conductive particle between parallel electrodes. We use a simple, capillary microfluidic platform that combines high-speed imaging with precision electrical measurements to enable the synchronized acquisition of both the particle location and the electric current due to particle motion. The experimental results are compared to those of a theoretical model, which relies on a Stokesian dynamics approach to accurately describe both the electrostatic and hydrodynamic problems governing particle motion. We find remarkable agreement between theory and experiment, suggesting that particle motion can be accurately captured by a combination of classical electrostatics and low-Reynolds number hydrodynamics. Building on this agreement, we offer new insight into the charge transfer process that occurs when the particle nears contact with an electrode surface. In particular, we find that the particle does not make mechanical contact with the electrode but rather that charge transfer occurs at finite surface separations of >0.1 ?m by means of an electric discharge through a thin lubricating film. We discuss the implications of these findings on the charging of the particle and its subsequent dynamics. PMID:25785396
Kevin W. Lawson; Douglas R. Lloyd
This paper provides a state-of-the-art review of the separation process known as membrane distillation, MD. An introduction to the terminology and fundamental concepts associated with MD as well as a historical review of the developments in MD are presented. Membrane properties, transport phenomena, and module design are discussed in detail. A critical evaluation of the MD literature is incorporated throughout
Luca Peliti
Contents: 1. Introduction 2. Amphiphilic molecules and the phases they form 3. Isolated membranes: the Helfrich hamiltonian 4. Vesicle shapes 5. Shape fluctuations in vesicles 6. Interacting fluid membranes 7. Conclusions A. Differential equations for vesicle shapes B. The Faddeev-Popov determinant C. One-loop calculation of the renormalization group D. The Liouville model
Dna electrophoresis in photopolymerized polyacrylamide gels on a microfluidic device
Lo, Chih-Cheng
DNA gel electrophoresis is a critical analytical step in a wide spectrum of genomic analysis assays. Great efforts have been directed to the development of miniaturized microfluidic systems (�lab-on-a-chip� systems) to perform low-cost, high...
A model for sample stacking in microcapillary DNA electrophoresis
Srivastava, Alok Kumar, 1967-
Sanger's method of chain termination is the method of choice in DNA sequencing, where electrophoresis is used to separate the different sized DNA. In the past decade, microfabricated capillary devices have been developed ...
The potential of high performance capillary electrophoresis (HPCE), especially in the free solution mode (FSCE), is demonstrated for the analysis/characterization of environmental humic substances (HUS). he very high efficiency of HPCE separations allows the production of electro...
21 CFR 862.2485 - Electrophoresis apparatus for clinical use.
Code of Federal Regulations, 2014 CFR
...for clinical use. (a) Identification. An electrophoresis apparatus for clinical use is a device intended to separate molecules or particles, including plasma proteins, lipoproteins, enzymes, and hemoglobulins on the basis of their net...
21 CFR 862.2485 - Electrophoresis apparatus for clinical use.
Code of Federal Regulations, 2012 CFR
...for clinical use. (a) Identification. An electrophoresis apparatus for clinical use is a device intended to separate molecules or particles, including plasma proteins, lipoproteins, enzymes, and hemoglobulins on the basis of their net...
21 CFR 862.2485 - Electrophoresis apparatus for clinical use.
Code of Federal Regulations, 2013 CFR
...for clinical use. (a) Identification. An electrophoresis apparatus for clinical use is a device intended to separate molecules or particles, including plasma proteins, lipoproteins, enzymes, and hemoglobulins on the basis of their net...
21 CFR 862.2485 - Electrophoresis apparatus for clinical use.
Code of Federal Regulations, 2011 CFR
...for clinical use. (a) Identification. An electrophoresis apparatus for clinical use is a device intended to separate molecules or particles, including plasma proteins, lipoproteins, enzymes, and hemoglobulins on the basis of their net...
Capillary Electrophoresis of DNA in Uncrosslinked Polymer Solutions
Barron, Annelise E.
per million (0.0006% (w/w)l of un- crosslinked hydroxyethyl cellulose (HEC) polymers-field electrophoresis; size separation is achieved by the application of low-voltage, pulsed elec- tric fields, which
Single molecule analysis of DNA electrophoresis in microdevices
Randall, Greg C
Given that current electrophoresis technology is inadequate for mapping large O[100 kilobasepair] DNA, several promising lab-on-chip designs for DNA mapping have been recently proposed that require either 1) a DNA molecule ...
Microchannel DNA Sequencing by End-Labelled Free Solution Electrophoresis
Barron, A.
The further development of End-Labeled Free-Solution Electrophoresis will greatly simplify DNA separation and sequencing on microfluidic devices. The development and optimization of drag-tags is critical to the success of this research.
Enumeration Algorithm for Determination of Binding Constants in Capillary Electrophoresis
Chen, David D.Y.
Enumeration Algorithm for Determination of Binding Constants in Capillary Electrophoresis Ning Fang and David D. Y. Chen* Department of Chemistry, University of British Columbia, Vancouver, BC, Canada V6T 1Z1
Procedures requiring extended periods of electrophoresis frequently require recirculation of the get buffer in order to reduce gel artifacts. ere we describe a recirculation device which can be built inexpensively and will fit many different model get boxes....
Non-linear electrophoresis of ideally polarizable particles
Chan, Wai Hong Ronald
This thesis investigates the non-linear regime of electrophoresis, in particular the variation of electrophoretic velocity with electric field at high field strengths. Known theoretical approaches to the problem accounting ...
Expression of acetate permease-like (apl) genes in subsurface communities of Geobacter species under fluctuating acetate concentrations
Elifantz, H.; N'Guessan, L.A.; Mouser, P.J.; Williams, K H.; Wilkins, M J.; Risso, C.; Holmes, D.E.; Long, P.E.; Lovley, D.R.
The addition of acetate to uranium-contaminated aquifers in order to stimulate the growth and activity of Geobacter species that reduce uranium is a promising in situ bioremediation option. Optimizing this bioremediation strategy requires that sufficient acetate be added to promote Geobacter species growth. We hypothesized that under acetate-limiting conditions, subsurface Geobacter species would increase the expression of either putative acetate symporters genes (aplI and aplII). Acetate was added to a uranium-contaminated aquifer (Rifle, CO) in two continuous amendments separated by 5 days of groundwater flush to create changing acetate concentrations. While the expression of aplI in monitoring well D04 (high acetate) weakly correlated with the acetate concentration over time, the transcript levels for this gene were relatively constant in well D08 (low acetate). At the lowest acetate concentrations during the groundwater flush, the transcript levels of aplII were the highest. The expression of aplII decreased 2-10-fold upon acetate reintroduction. However, the overall instability of acetate concentrations throughout the experiment could not support a robust conclusion regarding the role of apl genes in response to acetate limitation under field conditions, in contrast to previous chemostat studies, suggesting that the function of a microbial community cannot be inferred based on lab experiments alone.
Capillary Electrophoresis as a Fundamental Probe of Polymer Dynamics
George D. J. Phillies
Capillary electrophoresis has long been been recognized as a powerful analytic tool. Here it is demonstrated that the same capillary electrophoretic experiments also reveal dynamic properties of the polymer solutions being used as the support medium. The dependence of the electrophoretic mobility on the size of the probe and the properties of the matrix polymers shows a unity of behavior between electrophoresis and other methods of studying polymer properties.
Guidelines for reporting the use of gel electrophoresis in proteomics
Frank Gibson; Leigh Anderson; Gyorgy Babnigg; Mark Baker; Matthias Berth; Pierre-Alain Binz; Andy Borthwick; Phil Cash; Billy W Day; David B Friedman; Donita Garland; Howard B Gutstein; Christine Hoogland; Neil A Jones; Alamgir Khan; Joachim Klose; Angus I Lamond; Peter F Lemkin; Kathryn S Lilley; Jonathan Minden; Nicholas J Morris; Norman W Paton; Michael R Pisano; John E Prime; Thierry Rabilloud; David A Stead; Chris F Taylor; Hans Voshol; Anil Wipat; Andrew R Jones
the MIAPE Gel Electrophoresis (MIAPE-GE) guidelines specify the minimum information that should be provided when reporting the use of n-dimensional gel electrophoresis in a proteomics experiment. Developed through a joint effort between the gel-based analysis working group of the Human Proteome Organisation's Proteomics Standards Initiative (HUPO-PSI; http:\\/\\/www.psidev.info\\/) and the wider proteomics community, they constitute one part of the overall Minimum
Resistance of Streptococcus bovis to acetic acid at low pH: Relationship between intracellular pH and anion accumulation
Russell, J.B. (Cornell Univ., Ithaca, NY (USA))
Streptococcus bovis JB1, an acid-tolerant ruminal bacterium, was able to grown at pHs from 6.7 to 4.5, and 100 mM acetate had little effect on growth rate or proton motive force across the cell membrane. When S. bovis was grown in glucose-limited chemostats at pH 5.2, the addition of sodium acetate (as much as 100 mM) had little effect on the production of bacterial protein. At higher concentrations of sodium acetate (100 to 360 mM), production of bacterial protein declined, but this decrease could largely be explained by a shift in fermentation products (acetate, formate, and ethanol production to lactate production) and a decline in ATP production (3 ATP per glucose versus 2 ATP per glucose). Y{sub ATP} (grams of cells per mole at ATP) was not decreased significantly even by high concentrations of acetate. Cultures supplemented with 100 mM sodium acetate took up ({sup 14}C)acetate and ({sup 14}C)benzoate in accordance with the Henderson-Hasselbalch equation and gave similar estimates of intracellular pH. As the extracellular pH declined, S. bovis allowed its intracellular pH to decrease and maintained a relatively constant pH gradient across the cell membrane (0.9 unit). The decrease in intracellular pH prevented S. bovis from accumulating large amounts of acetate anion. On the basis of these results it did not appear that acetate was acting as an uncoupler. The sensitivity of other bacteria to volatile fatty acids at low pH is explained most easily by a high transmembrane pH gradient and anion accumulation.
Novel separation and detection methods of DNA fragments in electrophoresis
Chan, King Cheung.
A charge-coupled device (CCD) based electrophoresis system was developed. The system allowed non-destructive, sensitive, and on-line detection of native DNA in slab-gel electrophoresis via ultraviolet absorption measurement. The detection limit of double-stranded DNA fragment was 5 ng per band. Since the amount of DNA used in this experiment was typical, the CCD-based system could be readily implemented in molecular biology. Gel-filled and non-gel sieving capillary electrophoresis was developed for rapid and efficient separation of double-stranded DNA fragments. For the gel-filled CE separation a new gel matrix, the HydroLink gel (HL), was used. The HL capillary gel was easier to cast than the polyacrylamide capillary gel. For the non-gel separation, a GC capillary was used as the separation chamber, and cellulose additive was included in the electrophoresis as the sieving medium. Indirect fluorometry was applied in non-gel and gel electrophoresis for the detection of DNA fragments. This method allowed non-destructive and on-line detection of DNA during electrophoresis. The amount of DNA used with this method was comparable to those obtained with absorption measurement.
Novel separation and detection methods of DNA fragments in electrophoresis
Chan, K.C.
A charge-coupled device (CCD) based electrophoresis system was developed. The system allowed non-destructive, sensitive, and on-line detection of native DNA in slab-gel electrophoresis via ultraviolet absorption measurement. The detection limit of double-stranded DNA fragment was 5 ng per band. Since the amount of DNA used in this experiment was typical, the CCD-based system could be readily implemented in molecular biology. Gel-filled and non-gel sieving capillary electrophoresis (CE) was developed for rapid and efficient separation of double-stranded DNA fragments. For the gel-filled CE separation a new gel matrix, the HydroLink gel (HL), was used. The HL capillary gel was easier to cast than the polyacrylamide capillary gel. For the non-gel separation, a GC capillary was used as the separation chamber, and cellulose additive was included in the electrophoresis as the sieving medium. Indirect fluorometry was applied in non-gel and gel electrophoresis for the detection of DNA fragments. This method allowed nondestructive and on-line detection of DNA during electrophoresis. The amount of DNA used with this method was comparable to those obtained with absorption measurement.
Evaluation of cytogenetic and DNA damage caused by thallium(I) acetate in human blood cells.
Rodr�guez-Mercado, Juan J; Hern�ndez-de la Cruz, Heriberto; Felipe-Reyes, Miriam; Jaramillo-Cruz, Eduardo; Altamirano-Lozano, Mario A
Although thallium is detrimental to all living organisms, information regarding the mutagenic and genotoxic effects of this element and its compounds remains scarce. Therefore, we tested the genotoxic and cytotoxic effects of thallium(I) acetate on human peripheral blood cells in vitro using structural chromosomal aberrations (SCAs), sister chromatid exchanges (SCEs), and single-cell gel electrophoresis (at pH >13 or 12.1) analysis. Whole blood samples were incubated with 0.5, 1, 5, 10, 50, or 100 �g/mL thallium salt. Exposure to this metal compound resulted in a clear dose-dependent reduction in the mitotic and replicative indices. An increase in SCAs was evident in the treated group compared with the control group, and significant differences were observed in the percentage of cells with SCAs when metaphase cells were treated with 0.5-10 �g/mL of thallium(I). The SCE test did not reveal any significant differences. We observed that a 1-h treatment with thallium(I) at pH?>?13 significantly increased the comet length for all the concentrations tested; however, at pH 12.1, only the two highest concentrations affected the comet length. These results suggested that thallium(I) acetate induces cytotoxic, cytostatic, and clastogenic effects, as well as DNA damage. � 2013 Wiley Periodicals, Inc. Environ Toxicol, 2013. PMID:24318865
Characterization of DNA Damage in Yeast Apoptosis Induced by Hydrogen Peroxide, Acetic Acid, and Hyperosmotic Shock
Ribeiro, Gabriela F.; C�rte-Real, Manuela
Saccharomyces cerevisiae has been reported to die, under certain conditions, from programmed cell death with apoptotic markers. One of the most important markers is chromosomal DNA fragmentation as indicated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining. We found TUNEL staining in S. cerevisiae to be a consequence of both single- and double-strand DNA breaks, whereas in situ ligation specifically stained double-strand DNA breaks. Cells treated with hydrogen peroxide or acetic acid staining positively for TUNEL assay stained negatively for in situ ligation, indicating that DNA damage in both cases mainly consists of single-strand DNA breaks. Pulsed field gel electrophoresis of chromosomal DNA from cells dying from hydrogen peroxide, acetic acid, or hyperosmotic shock revealed DNA breakdown into fragments of several hundred kilobases, consistent with the higher order chromatin degradation preceding DNA laddering in apoptotic mammalian cells. DNA fragmentation was associated with death by treatment with 10 mM hydrogen peroxide but not 150 mM and was absent if cells were fixed with formaldehyde to eliminate enzyme activity before hydrogen peroxide treatment. These observations are consistent with a process that, like mammalian apoptosis, is enzyme dependent, degrades chromosomal DNA, and is activated only at low intensity of death stimuli. PMID:16899507
Acetate concentrations and oxidation in salt marsh sediments
NASA Technical Reports Server (NTRS)
Acetate concentrations and rates of acetate oxidation and sulfate reduction were measured in S. alterniflora sediments in New Hampshire and Massachusetts. Pore water extracted from cores by squeezing or centrifugation contained in greater than 0.1 mM acetate and, in some instances, greater than 1.0 mM. Pore water sampled nondestructively contained much less acetate, often less than 0.01 mM. Acetate was associated with roots, and concentrations varied with changes in plant physiology. Acetate turnover was very low whether whole core or slurry incubations were used. Radiotracers injected directly into soils yielded rates of sulfate reduction and acetate oxidation not significantly different from core incubation techniques. Regardless of incubation method, acetate oxidation did not account for a substantial percentage of sulfate reduction. These results differ markedly from data for unvegetated coastal sediments where acetate levels are low, oxidation rate constants are high, and acetate oxication rates greatly exceed rates of sulfate reduction. The discrepancy between rates of acetate oxidation and sulfate reduction in these marsh soils may be due either to the utilization of substrates other than acetate by sulfate reducers or artifacts associated with measurements of organic utilization by rhizosphere bacteria. Care must be taken when interpreting data from salt marsh sediments since the release of material from roots during coring may affect the concentrations of certain compounds as well as influencing results obtained when sediment incubations are employed.
Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins
ERIC Educational Resources Information Center
Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines
A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The�
Lithium acetate transformation of yeast Maitreya Dunham August 2004
Dunham, Maitreya
Lithium acetate transformation of yeast Maitreya Dunham August 2004 Original protocol from Katja until the OD600 is around 0.7-0.8 (~7 hours). Spin down the cells. Resuspend in 5 ml lithium acetate mix. Spin. Resuspend in 0.5 ml lithium acetate mix. Transfer to an eppendorf tube. Incubate 60 minutes
Influence of lead acetate on hypersensitivity. Experimental study.
Laschi-Loquerie, A; Descotes, J; Tachon, P; Evreux, J C
Recent studies showed that lead acetate has an important immunotoxicity for the phagocytic activity as well as humoral and cell-mediated immunity. We studied the influence of lead acetate on immediate and delayed hypersensitivity. The lead acetate exerts an important action on hypersensitivity reactions whether on rat mast cells degranulation (immediate hypersensitivity) or on contact hypersensitivity. PMID:6470497
DNA sequencing using fluorescence background electroblotting membrane
Caldwell, Karin D. (Salt Lake City, UT); Chu, Tun-Jen (Salt Lake City, UT); Pitt, William G. (Orem, UT)
A method for the multiplex sequencing on DNA is disclosed which comprises the electroblotting or specific base terminated DNA fragments, which have been resolved by gel electrophoresis, onto the surface of a neutral non-aromatic polymeric microporous membrane exhibiting low background fluorescence which has been surface modified to contain amino groups. Polypropylene membranes are preferably and the introduction of amino groups is accomplished by subjecting the membrane to radio or microwave frequency plasma discharge in the presence of an aminating agent, preferably ammonia. The membrane, containing physically adsorbed DNA fragments on its surface after the electroblotting, is then treated with crosslinking means such as UV radiation or a glutaraldehyde spray to chemically bind the DNA fragments to the membrane through said smino groups contained on the surface thereof. The DNA fragments chemically bound to the membrane are subjected to hybridization probing with a tagged probe specific to the sequence of the DNA fragments. The tagging may be by either fluorophores or radioisotopes. The tagged probes hybridized to said target DNA fragments are detected and read by laser induced fluorescence detection or autoradiograms. The use of aminated low fluorescent background membranes allows the use of fluorescent detection and reading even when the available amount of DNA to be sequenced is small. The DNA bound to the membrances may be reprobed numerous times.
Monitoring Insulin Aggregation via Capillary Electrophoresis
Pryor, Elizabeth; Kotarek, Joseph A.; Moss, Melissa A.; Hestekin, Christa N.
Early stages of insulin aggregation, which involve the transient formation of oligomeric aggregates, are an important aspect in the progression of Type II diabetes and in the quality control of pharmaceutical insulin production. This study is the first to utilize capillary electrophoresis (CE) with ultraviolet (UV) detection to monitor insulin oligomer formation at pH 8.0 and physiological ionic strength. The lag time to formation of the first detected species in the aggregation process was evaluated by UV-CE and thioflavin T (ThT) binding for salt concentrations from 100 mM to 250 mM. UV-CE had a significantly shorter (5�8 h) lag time than ThT binding (15�19 h). In addition, the lag time to detection of the first aggregated species via UV-CE was unaffected by salt concentration, while a trend toward an increased lag time with increased salt concentration was observed with ThT binding. This result indicates that solution ionic strength impacts early stages of aggregation and ?-sheet aggregate formation differently. To observe whether CE may be applied for the analysis of biological samples containing low insulin concentrations, the limit of detection using UV and laser induced fluorescence (LIF) detection modes was determined. The limit of detection using LIF-CE, 48.4 pM, was lower than the physiological insulin concentration, verifying the utility of this technique for monitoring biological samples. LIF-CE was subsequently used to analyze the time course for fluorescein isothiocyanate (FITC)-labeled insulin oligomer formation. This study is the first to report that the FITC label prevented incorporation of insulin into oligomers, cautioning against the use of this fluorescent label as a tag for following early stages of insulin aggregation. PMID:22272138
Assessment Guidelines for Managing Cellulose Acetate Collections
NSDL National Science Digital Library
Photographic negatives, motion picture film, microfilm, and sound recordings produced from the 1930s into the 1950s often used cellulose acetate as the transparent plastic carrier. As anyone who has ever come in contact with it well knows, its strong vinegar-like scent is hard to miss. Unfortunately, over time, the material is prone to deterioration, which eventually renders it unusable. In an effort to help guide libraries in Australia with this problem, the National Library of Australia has created this document. It provides assistance in identification of cellulose acetate (vs. other similar materials) and establishes criteria to assess condition, cultural importance, and use within the library or storage context. The document guides readers through the first step in a strategy for preserving these collections.
Leuprolide Acetate Suppresses Pedophilic Urges and Arousability
Justine M. Schober; Phyllis J. Kuhn; Paul G. Kovacs; James H. Earle; Peter M. Byrne; Ruth A. Fries
Cognitive�behavioral psychotherapy was compared with cognitive�behavioral psychotherapy augmented by leuprolide acetate (LA)\\u000a for suppression of pedophilic behavior. Five male pedophiles (M age, 50 years; range, 36�58) were administered LA by Depo injection for 12 months, followed by saline placebo for 12 months.\\u000a Testosterone levels, sexual interest preference by visual reaction time (Abel Assessment), penile tumescence (Monarch Penile\\u000a Plethysmography, PPG), as
Interconversion studies of betamethasone acetate polymorphs.
Ke, Xue; Ping, QiNeng; Shi, Hua
The polymorph interconversions of Betamethasone Acetate (BA) were studied under various pharmaceutical conditions, such as grinding, heating and suspending in water, based on differential scanning calorimetry, thermogravimetric analysis, and X-ray powder diffraction. There existed enantiotropic relationships between the three polymorphs of BA, which were named form II, Ialpha, and Ibeta work, respectively. It was concluded that form II was the most stable form when suspended in water. PMID:16221616
Corrosion of Stainless Steel During Acetate Production
J. S. Qi; G. C. Lester
Corrosion of types 304, 304L, 316, and 316L stainless steel (SS) during the esterification of acetic acid and alcohol or glycol ether was investigated. The catalyst for this reaction, sulfuric acid or para-toluene sulfonic acid (PTSA), was shown to cause more corrosion on reactor equipment than CH�COOH under the process conditions commonly practiced in industry. The corrosive action of the
Ulipristal acetate: the newest emergency contraceptive.
Wilton, Jeanne M
More than 50 percent of pregnancies in the United States are unplanned. Emergency contraception has been shown to possibly reduce the risk of pregnancy by as much as 75 percent. Ulipristal acetate is a selective progesterone receptor modulator that was approved by the U.S. Food and Drug Administration (FDA) for emergency contraceptive use in August 2010. This article reviews information on its mechanism of action, efficacy, safety and implications for women's health nurses. PMID:22900810
Ultrasound-assisted dyeing of cellulose acetate.
Udrescu, C; Ferrero, F; Periolatto, M
The possibility of reducing the use of auxiliaries in conventional cellulose acetate dyeing with Disperse Red 50 using ultrasound technique was studied as an alternative to the standard procedure. Dyeing of cellulose acetate yarn was carried out by using either mechanical agitation alone, with and without auxiliaries, or coupling mechanical and ultrasound agitation in the bath where the temperature range was maintained between 60 and 80 �C. The best results of dyeing kinetics were obtained with ultrasound coupled with mechanical agitation without auxiliaries (90% of bath exhaustion value at 80 �C). Hence the corresponding half dyeing times, absorption rate constants according to Cegarra-Puente modified equation and ultrasound efficiency were calculated confirming the synergic effect of sonication on the dyeing kinetics. Moreover the apparent activation energies were also evaluated and the positive effect of ultrasound added to mechanical agitation was evidenced by the lower value (48 kJ/mol) in comparison with 112 and 169 kJ/mol for mechanical stirring alone with auxiliaries and without, respectively. Finally, the fastness tests gave good values for samples dyed with ultrasound technique even without auxiliaries. Moreover color measurements on dyed yarns showed that the color yield obtained by ultrasound-assisted dyeing at 80 �C of cellulose acetate without using additional chemicals into the dye bath reached the same value yielded by mechanical agitation, but with remarkably shorter time. PMID:24457001
Characterization of Cupric Glutamate Extinguishing Mechanism of Alexandrium sp. LC3 with Two-dimensional Electrophoresis and MALDI-TOF MS
Hao Li; Jinlai Miao; Fengxia Cui; Guangyou Li
Mechanisms by which cupric glutamate, a novel algicide, extinguishes Alexandrium sp. LC3 are shown in this study. We show that cupric glutamate not only stimulated the production of malonaldehyde (MDA)\\u000a and dramatically promoted cell plasma membrane permeability (p?p?0.01). Analysis of protein expression profiles by two-dimensional electrophoresis (2-DE) indicated that only 47 protein\\u000a spots were detected in both control and cupric
... membranous nephropathy: Antinuclear antibodies test Anti-double-strand DNA, if the antinuclear antibodies test is positive Blood tests to check for hepatitis B, hepatitis C, and syphilis Complement levels Cryoglobulin test
Pyrolysis-GC/MS is used to evaluate the organic foulants found on two types of membranes for three natural waters. olyamide and cellulose acetate membranes are used. aters from Manatee Lake, Harsha Lake, and the Ohio River are used as feed waters. he pyrolysis fragments are class...
Measuring the zeta (electrokinetic) potential of reverse osmosis membranes by a streaming potential analyzer
Menachem Elimelech; William H. Chen; John J. Waypa
SUMMARY The use of a novel streaming potential analyzer to measure the zeta potential of cellulose acetate and composite polyamide reverse osmosis membranes is reported. Zeta potentials of these membranes were measured at various solution chemistries. These include effects of salt (NaCl) concentration, solution pH, and the presence of dissolved humic substances. It is demonstrated that streaming potential is a
Fouling of reverse osmosis membranes by hydrocarbonated and fluorinated surfactants contained in firefighting water
Paris-Sud XI, Universit� de
Title: Fouling of reverse osmosis membranes by hydrocarbonated and fluorinated surfactants osmosis efficiently treated the water from fire extinguishment. In this work we focused on the reverse osmosis step. Polyamide and cellulose acetate membrane materials were screened in a flat sheet cell
Preparation of a Transdermal Delivery System and Effect of Membrane Type for Scopolamine Drug
Hassan Arabi; Ali Hashemi; Navid Ajdari
The aim of this study was to clarify the performance of a membrane control- led reservoir system (MCRS) for scopolamine hydrobromide (SH) under in vitro condition by determination of the role of membrane on SH rate control. In this method SH was incorporated into two polymers (polyisobutylene and polybutyl acrylate) and SH rate across ethylene-vinyl acetate copolymer (EVA) and ethyl
Accumulation of organochlorine pesticides by semipermeable membrane devices using composite complex
Long B. Liao; Xian M. Xiao
Semipermeable membrane devices (SPMDs) were developed for passive in situ monitoring of organochlorine pesticides (OCPs) in aqueous solution in both laboratory and field (Pearl River Delta, China) studies. The device consisted of a thin film of neutral lipid triolein, enclosed in thin-walled tubing made of composite cellulose acetate membrane (CA) supported by linear low density polyethylene (LLDPE) (CAPE). Results from
Boyer, Edmond
that remain attached to the membrane when it is removed from the shell with diaminoethanetetra-acetic acidA STUDY OF THE COMPOSITION OF HEN'S EGG-SHELL MEMBRANES D.-A. BALCH Rosemarie A. COOKE Department of Physiology and Biochemistry, The University, Reading, Berkshire (Great-Britain) INTRODUCTION The egg-shell
Analysis of diterpenoic compounds in natural resins applied as binders in museum objects by capillary electrophoresis.
Findeisen, Anna; Kolivoska, Viliam; Kaml, Isabella; Baatz, Wolfgang; Kenndler, Ernst
The exudates of conifers consist mainly of diterpenoic acids of the abietane and pimarane type (abietic, neoabietic, dehydroabietic, palustric, pimaric, isopimaric, levopimaric and sandaracopimaric acid) and larixol acetate. These natural resins were used as adhesives, coatings, varnishes or plasticizers in artistic and historic works since ancient times. For the purpose of conservation and restoration and for art historic examination of such museum objects the identification of the binding media used is undoubtedly of paramount importance. In the present paper, the characterization of these resins based on the pattern of their diterpenoid constituents is carried out by capillary electrophoresis. For separation a background electrolyte which has been initially introduced for the analysis of chlorinated and natural resin acids in waste water was modified and the experimental conditions were adjusted in terms of resolution and analysis time. Separation was carried out in borate buffer at pH 9.25 (ionic strength 20 mmol L(-1)) with methyl-beta-cyclodextrin and sulfobutylether-beta-cyclodextrin as additives to increase selectivity and enhance the solubility of the analytes. With this electrophoretic system the resin acids of interest and larixol acetate--all as anionic cyclodextrin complexes--were separated within 5 min and detected at 200, 250 and 270 nm with a diode array detector. The electrophoretic patterns served for the characterisation of the relevant diterpenoic resins, balsams and copals. Sample pre-treatment was limited to sonication in methanol at 55 degrees C for 30 min. This enables the identification of the resins in mixtures with other binders like plant gums, animal glues or drying oils, even when these media are present in excess. Colophony was identified as resinous constituent of a modelling mass for gilded frames originating from the 19th century. PMID:17521659
Review of electrophoresis and BioMEMS in 2007: American Electrophoresis Society 24th Annual Meeting.
Minerick, Adrienne R; Ugaz, Victor M; Murthy, Shashi K; Posner, Jonathan D
Researchers came together for the 24th Annual Meeting of the American Electrophoresis Society (AES), which was held November 4-9, 2007, at the Salt Palace Convention Center in Salt Lake City, UT, U.S.A. The Annual AES meeting is held in conjunction with the annual meeting of the American Institute of Chemical Engineers (AIChE). This year's meeting had a significant emphasis on theoretical and experimental advances in Biological Micro Electro Mechanical Systems (BioMEMS), electrokinetics, and proteomics technologies. A total of 15 sessions were held, within which 71 presentations and 18 posters were discussed. This review provides a brief sampling of the exciting research presented at the conference. PMID:18982910
Recent Developments in Instrumentation for Capillary Electrophoresis and Microchip-Capillary Electrophoresis
Felhofer, Jessica L.; Blanes, Lucas; Garcia, Carlos D.
Over the last years there has been an explosion in the number of developments and applications of capillary electrophoresis (CE) and microchip-CE. In part, this growth has been the direct consequence of recent developments in instrumentation associated with CE. This review, which is focused on contributions published in the last five years, is intended to complement the papers presented in this special issue dedicated to Instrumentation and to provide an overview on the general trend and some of the most remarkable developments published in the areas of high voltage power supplies, detectors, auxiliary components, and compact systems. It also includes few examples of alternative uses of and modifications to traditional CE instruments. PMID:20665910
Sensitivity of prestaining RNA with ethidium bromide before electrophoresis and performance of subsequent northern blots using heterologous DNA probes.
Zhao, Yun; Du, Linfang; Zhang, Nianhui
Adding ethidium bromide (EtBr) at low concentrations to RNA samples before running formaldehyde-agarose gels affords the advantages of checking RNA integrity and evaluating the quality of size-separation at any time during electrophoresis or immediately after either electrophoresis or blotted the separated RNA onto the membrane without significantly compromising mobility, transfer, or hybridization. In this study, we systematically examined the factors that affect the sensitivity of RNA prestaining by heating RNA samples that include EtBr before electrophoresis under different denaturation conditions. We also examined the efficiency of the hybridization of EtBr-prestained RNA with heterologous DNA probes. The results showed that the fluorescent intensity of EtBr-prestained RNA was affected not only by the EtBr concentration as previously reported but also by the RNA amount, denaturation time, and denaturation temperature. Prior staining of RNA with 40�?g/mL EtBr significantly decreased the efficiency of Northern blot hybridization with heterologous DNA probes. We propose that to best combine staining sensitivity and the efficiency of Northern blot hybridization with heterologous DNA probes, the concentration of EtBr used to prestain RNA should not exceed 30�?g/mL. The efficiency of the hybridization of EtBr-prestained RNA was affected not only by factors that affect staining sensitivity but also by the type of probe used. PMID:22585558
Silver(I)-mediated separations by capillary zone electrophoresis and micellar electrokinetic chromatography: argentation electrophoresis.
Wright, P B; Dorsey, J G
The addition of Ag(I) to the run buffer in capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC), containing sodium dodecyl sulfate, applies the principles of argentation chromatography to electrophoretic separations and is termed "argentation electrophoresis". This technique is shown to provide a complementary method to CZE and MEKC for the separation of specific types of solutes that selectively complex with Ag(I). Baseline resolution in the CZE separation of nine sulfonamides is achieved by the addition of 50 mM silver nitrate to the run buffer. Retention mechanisms in MEKC separations can also be manipulated by the addition of Ag(I) to the micellar solution. Only slight resolution of a pair of sulfonamides was achieved under normal MEKC conditions. Upon the addition of Ag(I) to the mobile phase containing SDS micelles, baseline resolution of the compounds is shown. The retention order and resolution of five sulfonamides changed significantly when 25 mM Ag(I) was added to the SDS-containing buffer. The use of Ag(I) addition in MEKC is also applied to the separation of various other compounds that show selectivity toward Ag(I) complexation, including S-containing heterocycles and vitamin D compounds. The effect of the addition of Ag(I) on the elution range in MEKC is also investigated. A steady increase in the elution range is seen upon increasing the concentration of Ag(I). With a constant percentage of organic modifier (15%), the addition of higher concentrations of silver nitrate (25-50 mM) results in elution ranges greater than 12. The results using Ag(I) as buffer additives in MEKC are also compared to studies utilizing a mixed counterion surfactant of sodium/silver dodecyl sulfate. PMID:8712354
Differential Membrane Proteome Analysis Reveals Novel Proteins Involved in the Degradation of Aromatic Compounds in Geobacter metallireducens*
Heintz, Dimitri; Gallien, S�bastien; Wischgoll, Simon; Ullmann, Anja Kerstin; Schaeffer, Christine; Kretzschmar, Antje Karen; van Dorsselaer, Alain; Boll, Matthias
Aromatic compounds comprise a large class of natural and man-made compounds, many of which are of considerable concern for the environment and human health. In aromatic compound-degrading anaerobic bacteria the central intermediate of aromatic catabolism, benzoyl coenzyme A, is attacked by dearomatizing benzoyl-CoA reductases (BCRs). An ATP-dependent BCR has been characterized in facultative anaerobes. In contrast, a previous analysis of the soluble proteome from the obligately anaerobic model organism Geobacter metallireducens identified genes putatively coding for a completely different dearomatizing BCR. The corresponding BamBCDEFGHI complex is predicted to comprise soluble molybdenum or tungsten, selenocysteine, and FeS cluster-containing components. To elucidate key processes involved in the degradation of aromatic compounds in obligately anaerobic bacteria, differential membrane protein abundance levels from G. metallireducens grown on benzoate and acetate were determined by the MS-based spectral counting approach. A total of 931 proteins were identified by combining one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis with liquid chromatography-tandem mass spectrometry. Several membrane-associated proteins involved in the degradation of aromatic compounds were newly identified including proteins with similarities to modules of NiFe/heme b-containing and energy-converting hydrogenases, cytochrome bd oxidases, dissimilatory nitrate reductases, and a tungstate ATP-binding cassette transporter system. The transcriptional regulation of differentially expressed genes was analyzed by quantitative reverse transcription-PCR; in addition benzoate-induced in vitro activities of hydrogenase and nitrate reductase were determined. The results obtained provide novel insights into the poorly understood degradation of aromatic compounds in obligately anaerobic bacteria. PMID:19497847
Electrophoresis of DNA and other polyelectrolytes: Physical mechanisms
NASA Astrophysics Data System (ADS)
Viovy, Jean-Louis
The dramatic recent advances in molecular biology, which have opened a new era in medicine and biotechnology, rely on improved techniques to study large molecules. Electrophoresis is one of the most important of these. Separation of DNA by size, in particular, is at the heart of genome mapping and sequencing and is likely to play an increasing role in diagnosis. This article reviews, from the point of view of a physicist, the mechanisms responsible for electrophoretic separation of polyelectrolytes. This separation is mainly performed in gels, and a wide variety of migration mechanisms can come into play, depending on the polyelectrolyte's architecture, on the electric fields applied, and on the properties of the gel. After a brief review of the thermodynamic and electrohydrodynamic principles relating to polyelectrolyte solutions, the author treats the phenomenology of electrophoresis and describes the conceptual and theoretical tools in the field. The reptation mechanisms, by which large flexible polyelectrolytes thread their way through the pores of the gel matrix, play a prominent role. Biased reptation, the extension of this model to electrophoresis, provides a very intuitive framework within which numerous physical ideas can be introduced and discussed. It has been the most popular theory in this domain, and it remains an inspiring concept for current development. There have also been important advances in experimental techniques such as single-molecule viodeomicroscopy and the development of nongel separation media and mechanisms. These, in turn, form the basis for fast-developing and innovative technologies like capillary electrophoresis, electrophoresis on microchips, and molecular ratchets.
Analysis of lysozyme in cheese samples by on-line combination of capillary zone electrophoresis and mass spectrometry.
Kondekov�, Monika; Maier, V�t?zslav; Ginterov�, Pavl�na; Mar�k, Jozef; Sev?�k, Juraj
Some methodological aspects of an on-line combination of capillary zone electrophoresis with mass spectrometric detection (CZE-QqQ-MS) were studied in this work as well as the possibilities of using this combination for analysis of the high-molecular mass compounds present in multi-component matrices. All experiments using an on-line combination of capillary electrophoresis with mass spectrometric detection were carried out in cationic mode in covalently-coated capillary. The optimised electrolyte system consisted of 100 mmol/L formic acid. Prior to the CZE-QqQ-MS analysis, an extraction of lysozyme from cheese samples using 1 mol/L of acetic acid was performed. The LOD was 3.6 mg lysozyme per kg and the LOQ was 10.9 mg lysozyme per kg. The concentration range of the lysozyme determined in four cheese samples analysed in this work was from 0.5 to 3.3g of lysozyme per kg. The values of the relative standard deviations thus obtained were from 4.6% to 9.3% depending on the cheese sample. PMID:24491746
Quantification of terbinafine in pharmaceutical tablets using capillary electrophoresis with contactless conductivity detection and batch injection analysis with amperometric detection.
Felix, Fabiana S; Ferreira, Lu�s M C; Rossini, Pamela de O; do Lago, Claudimir L; Angnes, L�cio
Terbinafine hydrochloride (TerbHCl) is an allylamine derivative with fungicidal action, especially against dermatophytes. Different analytical methods have been reported for quantifying TerbHCl in different samples. These procedures require time-consuming sample preparation or expensive instrumentation. In this paper, electrochemical methods involving capillary electrophoresis with contactless conductivity detection, and amperometry associated with batch injection analysis, are described for the determination of TerbHCl in pharmaceutical products. In the capillary electrophoresis experiments, terbinafine was protonated and analyzed in the cationic form in less than 1 min. A linear range from 1.46 to 36.4 ?g mL(-1) in acetate buffer solution and a detection limit of 0.11 ?g mL(-1) were achieved. In the amperometric studies, terbinafine was oxidized at +0.85 V with high throughput (225 injection h(-1)) and good linear range (10-100 ?mol L(-1)). It was also possible to determine the antifungal agent using simultaneous conductometric and potentiometric titrations in the presence of 5% ethanol. The electrochemical methods were applied to the quantification of TerbHCl in different tablet samples; the results were comparable with values indicated by the manufacturer and those found using titrimetry according to the Pharmacopoeia. The electrochemical methods are simple, rapid and an appropriate alternative for quantifying this drug in real samples. PMID:23158315
Acetate supplementation attenuates lipopolysaccharide-induced neuroinflammation
Reisenauer, Chris J.; Bhatt, Dhaval P.; Mitteness, Dane J.; Slanczka, Evan R.; Gienger, Heidi M.; Watt, John A.; Rosenberger, Thad A.
Glyceryl triacetate (GTA), a compound effective at increasing circulating and tissue levels of acetate was used to treat rats subjected to a continual 28 day intra-ventricular infusion of bacterial lipopolysaccharide (LPS). This model produces a neuroinflammatory injury characterized by global neuroglial activation and a decrease in choline acetyltransferase immunoreactivity in the basal forebrain. During the LPS infusion, rats were given a daily treatment of either water or GTA at a dose of 6g/kg by oral gavage. In parallel experiments free-CoA and acetyl-CoA levels were measured in microwave fixed brains and flash frozen heart, liver, kidney and muscle following a single oral dose of GTA. We found that a single oral dose of GTA significantly increased plasma acetate levels by 15 min and remained elevated for up to 4 hr. At 30 min the acetyl-CoA levels in microwave-fixed brain and flash frozen heart and liver were increased at least 2.2-fold. The concentrations of brain acetyl-CoA was significantly increased between 30 and 45 min following treatment and remained elevated for up to 4 hr. The concentration of free-CoA in brain was significantly decreased compared to controls at 240 min. Immunohistochemical and morphological analysis demonstrated that a daily treatment with GTA significantly reduced the percentage of reactive GFAP-positive astrocytes and activated CD11b-positive microglia by 40�50% in rats subjected to LPS-induced neuroinflammation. Further, in rats subjected to neuroinflammation, GTA significantly increased the number of ChAT-positive cells by 40% in the basal forebrain compared to untreated controls. These data suggest that acetate supplementation increases intermediary short chain acetyl-CoA metabolism and that treatment is potentially anti-inflammatory and neuroprotective with regards to attenuating neuroglial activation and increasing ChAT immunoreactivity in this model. PMID:21272004
An evaluation of membrane materials for the treatment of highly concentrated suspended salt solutions in reverse osmosis and nanofiltration processes for desalination
Hughes, Trenton Whiting
membrane materials that are most suitable for the process. In the study, a one plate SEPA Cell module by GE Osmonics was used to determine which membranes were most susceptible to fouling and/or membrane hydrolysis. A cellulose acetate (CA), polyamide (PA...
Migration behaviour of discontinuous buffers in capillary electrophoresis during protein enrichment.
Li, Ting; Booker, Christina J; Yeung, Ken K-C
Capillary electrophoresis (CE) is not only an effective separation technique, but can also serve as a sample preparation tool for enrichment and purification at sub-microliter sample volumes. Our approach is based on the use of a discontinuous buffer system consisting of an acid and a base (acetate and ammonium). Proteins and/or peptides with isoelectric points between the pH values of these two buffers will become stacked at the neutralization reaction boundary (NRB). To understand the mechanism of the NRB formation and the electrophoretic migration of various ions during the enrichment, we performed experiments using myoglobin and mesityl oxide to reveal the ion migration patterns at the buffer junction, and utilized Simul 5 to computer simulate the process. The simulated results closely resembled the experimental data, and together, they effectively revealed the characteristics of the discontinuous buffers. Importantly, the discovery allowed the manipulation of NRB behaviours by controlling the discontinuous buffer composition. To illustrate this, the removal of urea as an unwanted background molecule from the enriched protein sample was achieved based on the acquired information. PMID:22919699
DNA capillary electrophoresis using poly(vinyl alcohol). I. Inner capillary coating.
Moritani, Tohei; Yoon, Kyunghwan; Rafailovich, Miriam; Chu, Benjamin
Two new methods of inner capillary coating with poly(vinyl alcohol) (PVAL) have been investigated and evaluated by performing DNA capillary electrophoresis (CE) using PVAL as a separation medium and by measuring the electroosmotic flow (EOF) mobility. The treatment of capillaries with a silanol-group modified PVAL (PVAL-Si) has been found to give good coating effects for improving the resolution of DNA CE and for reducing the EOF. This coating must be effectively achieved by combining the adsorptive property of PVAL chains onto silica with the reaction between the silanol groups of PVAL-Si and the silica surface. The adsorption of PVAL onto silica has been observed by using atomic force microscopy (AFM) for PVAL-Si as well as for a nonmodified PVAL as a control. The coating with PVAL that links to the capillary wall surface with more hydrolytically stable bonding, -Si-C-, has been formed by performing the Grignard reaction, followed by in-capillary polymerization of vinyl acetate (VAc) and hydrolysis. This coating has been found to be effective for improving the resolution of DNA CE and for reducing the EOF. PMID:12929172
Chiral recognition of dapoxetine enantiomers with methylated-gamma-cyclodextrin: a validated capillary electrophoresis method.
Neumajer, G�bor; Sohajda, Tam�s; Darcsi, Andr�s; T�th, Gerg?; Szente, Lajos; Nosz�l, B�la; B�ni, Szabolcs
The enantiomers of dapoxetine, a serotonin transporter inhibitor for the treatment of premature ejaculation have been separated by cyclodextrin modified capillary zone electrophoresis using uncoated fused-silica capillary. Over 20 cyclodextrins were screened as chiral selectors, investigating the stability of the inclusion complexes and enantioseparating properties. According to the preliminary experiments as chiral selector randomly methylated-?-cyclodextrin was chosen. The basic chemical and instrumental parameters of enantioseparation as concentration of buffer, chiral selector and organic additive, pH, temperature and applied voltage were optimized afterwards using an orthogonal experimental design. Using this methodology not only the optimal parameter values for chiral separation (15 �C, +15 kV, 70 mM acetate, 20 v/v% MeOH, pH*=4.5, 3 mM methylated-?-CyD) but also the significance order of factors on resolution was determined. Applying these parameters an optimal resolution of 7.01 was achieved. The optimized method was then validated according to the ICH guideline Q2 (R1) with regard to repeatability, linearity range, LOD, LOQ, accuracy and robustness. PMID:22280959
Quantitative Determination of Lercanidipine Enantiomers in Commercial Formulations by Capillary Electrophoresis
Louren�o, Luciana Pereira; Aguiar, Fernando Armani; de Oliveira, Anderson Rodrigo Moraes; de Gaitani, Cristiane Masetto
An enantioselective method based on capillary electrophoresis (CE) using cyclodextrin (CD) as chiral selector was developed and validated for determination of lercanidipine (LER) enantiomers, a drug calcium channel blocker which exerts antihypertensive effects of long duration, in a pharmaceutical formulation. Optimum separation of LER enantiomers was obtained on a 50?cm � 50??m id capillary using a sodium acetate buffer solution 200?mmol/L pH 4.0 containing 10?mmol/L of 2,3,6-o-methyl-?-cyclodextrin (TM-?-CD) as background electrolyte. The capillary temperature and voltage were 15�C and 25?kV, respectively, hydrodynamic injection and detection at 237?nm. Linearity was obtained in the range 12.5�100??g/mL for both enantiomers (r ? 0.995). The RSD (%) and relative errors (E, %) obtained in precision and accuracy studies (intraday and interday) were lower than 5%. After validation, the method was applied to quantify the enantiomers of LER in commercial tablets and the results were satisfactory in terms of accuracy and precision, both less than 5%. Therefore, this method was found to be appropriate for enantioselective quality control of LER enantiomers in pharmaceutical formulations.
Bacterial community dynamics of salted and fermented shrimp based on denaturing gradient gel electrophoresis.
Han, Kook-Il; Kim, Yong Hyun; Hwang, Seon Gu; Jung, Eui-Gil; Patnaik, Bharat Bhusan; Han, Yeon Soo; Nam, Kung-Woo; Kim, Wan-Jong; Han, Man-Deuk
The Korean traditional seafood jeotgal is consumed directly or as an additive in other foods to improve flavor or fermentation efficiency. Saeujot, made from salted and fermented tiny shrimp (SFS; Acetes japonicus), is the best-selling jeotgal in Korea. In this study, we reveal the microbial diversity and dynamics in naturally fermented shrimp by denaturing gradient gel electrophoresis (DGGE). The population fingerprints of the predominant microbiota and its succession were generated by DGGE analysis of universal V3 16S rDNA polymerase chain reaction (PCR) amplicons. Overall, 17 strains were identified from sequencing of 30 DGGE bands. The DGGE profiles showed diverse bacterial populations in the sample, throughout the fermentation of SFS. Staphylococcus equorum, Halanaerobium saccharolyticum, Salimicrobium luteum, and Halomonas jeotgali were the dominant bacteria, and their levels steadily increased during the fermentation process. Certain other bacteria, such as Psychrobacter jeotgali and Halomonas alimentaria appeared during the early-fermentation process, while Alkalibacterium putridalgicola, Tetragenococcus muriaticus, and Salinicoccus jeotgali appeared during the late-fermentation process. The members of the order Bacillales were found to be predominant during the fermentation of SFS. Furthermore, S. equorum was identified as the dominant bacterial isolate by the traditional method of culturing under aerobic and facultative anaerobic conditions. We expect that this information will facilitate the design of autochthonous starter cultures for the production of SFS with desired characteristic sensory profiles and shorter ripening times. PMID:25393163
Electrophoresis for the analysis of heparin purity and quality
Volpi, Nicola; Maccari, Francesca; Suwan, Jiraporn; Linhardt, Robert J.
The adulteration of raw heparin with oversulfated chondroitin sulfate (OSCS) in 2007�2008 produced a global crisis resulting in extensive revisions to the pharmacopeia monographs and prompting the FDA to recommend the development of additional methods for the analysis of heparin purity. As a consequence, a wide variety of innovative analytical approaches have been developed for the quality assurance and purity of unfractionated and low-molecular-weight heparins. This review discusses recent developments in electrophoresis techniques available for the sensitive separation, detection, and partial structural characterization of heparin contaminants. In particular, this review summarizes recent publications on heparin quality and related impurity analysis using electrophoretic separations such as capillary electrophoresis (CE) of intact polysaccharides and hexosamines derived from their acidic hydrolysis, and polyacrylamide gel electrophoresis (PAGE) for the separation of heparin samples without and in the presence of its relatively specific depolymerization process with nitrous acid treatment. PMID:22736353
This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project was to try to detect unstained, untagged, unlabeled DNA bands in real-time during gel electrophoresis using simple thermal measurements. The technical and ES&H advantages to this approach could potentially be quite significant, especially given the extreme importance of gel electrophoresis to a wide variety of practical and research fields. The project was unable to demonstrate sufficient thermal sensitivity to detect DNA bands. It is clear that we still do not understand the gel electrophoresis phenomenon very well. The temperature control techniques developed during the course of this project have other useful applications.
Preparative cell electrophoresis at 1 and 0 gravity
NASA Technical Reports Server (NTRS)
Van Oss, C. J.; Bronson, P. M.
It is attempted to show that the use of heavy water (D2O) as starting cushion for the cells combines the advantages of the required density difference, with no lasting biochemical or physiochemical influence on the cells. Phosphate buffers of low ionic strength were prepared in distilled water or heavy water. A vertical starch gel electrophoresis was used to support a cylindrical polystyrene electrophoresis tube used for lymphocyte separations, 25 cm in length and 0.75 cm I.D., prepared from a 10 ml disposable pipet. Erythrocyte separations were carried out in a jacketed rectangular plexiglas chamber. It is pointed out that the described preparative D2O gradient electrophoresis method cannot be readily used for the measurement of electrophoretic mobilities for analytical purposes. However, for the preparative separation of cells with only slightly different electrokinetic properties the method appears promising, simple, and entirely inocuous to the cells.
Analysis of Common Household Cleaner-Disinfectants by Capillary Electrophoresis
NASA Astrophysics Data System (ADS)
Gardner, William P.; Girard, James E.
The use of capillary electrophoresis (CE) as an analytical technique in research, industrial, and commercial laboratories is growing rapidly. It is therefore very important to expose undergraduate instrumental analysis students to capillary electrophoresis. In this report we describe the CE analysis for benzalkonium compounds in common household cleaners and disinfectants. The surfactant nature of the benzalkonium compounds is the key consideration in performing the analysis, and modifications to the CE running buffer must be performed in order to successfully analyze the products. This experiment also illustrates the importance of (i) using peak areas corrected for variations in migration time to improve accuracy and (ii) using internal standards to improve the precision of capillary electrophoresis results.
Two-dimensional gel electrophoresis and immunoblotting of Campylobacter pylori proteins.
Dunn, B E; Perez-Perez, G I; Blaser, M J
Whole-cell, outer-membrane protein, flagellum-associated antigens and partially purified urease of Campylobacter pylori were analyzed by two-dimensional gel electrophoresis. C. pylori strains were readily distinguished from strains of Campylobacter jejuni, C. coli, and C. fetus by absence of major outer membrane proteins with Mrs of 41,000 to 45,000. C. pylori strains also lacked the acidic surface-array proteins at Mr 100,000 to 149,000 identified previously in serum-resistant strains of C. fetus. Surface labeling of intact C. pylori cells with 125I revealed two common major proteins, which we have designated protein 2 (pI 5.6 to 5.8, Mr 66,000) and protein 3 (pI 5.2 to 5.5, Mr 63,000). Proteins 2 and 3 were also the major components (subunits) observed in partially purified urease. Partially purified preparations of flagella consistently contained proteins 2 and 3. Thus, urease appears to be associated with both outer membranes and flagella of C. pylori. C. pylori strains also possessed an antigen at Mr 59,000 which was cross-reactive with antiserum against flagella of C. jejuni. However, the antigen did not appear to be associated with flagella per se in C. pylori. Protein 2 was unique to C. pylori among the Campylobacter species studied. It was not recognized by antibody against whole cells of C. jejuni or C. fetus or flagella of C. jejuni. Protein 3 was cross-reactive with antiserum against whole cells of C. jejuni and C. fetus, as were several other major protein antigens. Because protein 2 is a major outer membrane protein that is apparently unique to C. pylori, development of monospecific antibodies against this antigen may be useful for the identification of C. pylori in tissues, and purified antigen may be useful for serologic tests for specific diagnosis of C. pylori infections. PMID:2722241
A. Aurilia; E. Spallucci
A metal ring removed from a soap-water solution encloses a film of soap which can be mathematically described as a minimal surface having the ring as its only boundary. This is known to everybody. In this letter we suggest a relativistic extension of the above fluidodynamic system where the soap film is replaced by a Kalb-Ramond gauge potential $\\b(x)$ and the ring by a closed string. The interaction between the $\\b$-field and the string current excites a new configuration of the system consisting of a relativistic membrane bounded by the string. We call such a classical solution of the equation of motion an axionic membrane. As a dynamical system, the axionic membrane admits a Hamilton-Jacobi formulation which is an extension of the H-J theory of electromagnetic strings.
Exploring chip-capillary electrophoresis-laser-induced fluorescence field-deployable platform flexibility: separations of fluorescent dyes by chip-based non-aqueous capillary electrophoresis.
Nuchtavorn, Nantana; Smejkal, Petr; Breadmore, Michael C; Guijt, Rosanne M; Doble, Philip; Bek, Fritz; Foret, Frantisek; Suntornsuk, Leena; Macka, Mirek
Microfluidic chip electrophoresis (chip-CE) is a separation method that is compatible with portable and on-site analysis, however, only few commercial chip-CE systems with laser-induced fluorescence (LIF) and light emitting diode (LED) fluorescence detection are available. They are established for several application tailored methods limited to specific biopolymers (DNA, RNA and proteins), and correspondingly the range of their applications has been limited. In this work we address the lack of commercially available research-type flexible chip-CE platforms by exploring the limits of using an application-tailored system equipped with chips and methods designed for DNA separations as a generic chip-CE platform - this is a very significant issue that has not been widely studied. In the investigated Agilent Bioanalyzer chip-CE system, the fixed components are the Agilent chips and the detection (LIF at 635 nm and LEDIF at 470 nm), while the chemistry (electrolyte) and the programming of all the high voltages are flexible. Using standard DNA chips, we show that a generic CE function of the system is easily possible and we demonstrate an extension of the applicability to non-aqueous CE (NACE). We studied the chip compatibility with organic solvents (i.e. MeOH, ACN, DMF and DMSO) and demonstrated the chip compatibility with DMSO as a non-volatile and non-hazardous solvent with satisfactory stability of migration times over 50h. The generic CE capability is illustrated with separations of fluorescent basic blue dyes methylene blue (MB), toluidine blue (TB), nile blue (NB) and brilliant cresyl blue (BC). Further, the effects of the composition of the background electrolyte (BGE) on the separation were studied, including the contents of water (0-30%) and buffer composition. In background electrolytes containing typically 80 mmol/L ammonium acetate and 870 mmol/L acetic acid in 100% DMSO baseline separation of the dyes were achieved in 40s. Linearity was documented in the range of 5-28 ?mol/L, 10-100 ?mol/L, 1.56-50 nmol/L and 5-75 nmol/L (r(2) values in the range 0.974-0.999), and limit of detection (LOD) values were 90 nmol/L, 1 ?mol/L 1.4 nmol/L, and 2 nmol/L for MB, TB, NB and BC, respectively. PMID:23510955
Membrane potential in charged porous membranes
P Fievet; B Aoubiza; A Szymczyk; J Pagetti
For charged porous membranes, the separation efficiency to charged particles and ions is affected by the electrical properties of the membrane surface. Such properties are most commonly quantified in terms of zeta-potential. In this paper, it is shown that the zeta-potential can be calculated numerically from the membrane potential. The membrane potential expression for charged capillary membranes in contact with
Preparation of PDMS�Silica Nanocomposite Membranes with Silane Coupling for Recovering Ethanol by Pervaporation
Ping Peng; Baoli Shi; Yongqiang Lan
In this article, the composite polydimethylsiloxane (PDMS) membranes supported by cellulose-acetate (CA) microfiltration membrane were successfully prepared by adding nano-fumed silica particles modified with a silane coupling reagent, NH2-C3H6-Si(OC2H5)3. The effects of silica content, feed concentration, and feed temperature on the pervaporation performances of the nano-composite PDMS membranes were investigated for recovering ethanol from aqueous solution by pervaporation. It was
Gel Electrophoresis of Gold-DNA Nano-Conjugates
Pellegrino, T.; Sperling, R.A.; Alivisatos, A.P.; Parak, W.J.
Single stranded DNA of different lengths and different amounts was attached to colloidal phosphine stabilized Au nanoparticles. The resulting conjugates were investigated in detail by a gel electrophoresis study based on 1200 gels. We demonstrate how these experiments help to understand the binding of DNA to Au particles. In particular we compare specific attachment of DNA via gold-thiol bonds with nonspecific adsorption of DNA. The maximum number of DNA molecules that can be bound per particle was determined. We also compare several methods to used gel electrophoresis for investigating the effective diameter of DNA-Au conjugates, such as using a calibration curve of particles with known diameters and Ferguson plots.
Fenofibrate and fenofibric acid analysis by capillary electrophoresis.
Shihabi, Zak K
A capillary electrophoresis method has been developed to measure fenofibrate in capsules based on micellar electrokinetic capillary chromatography with detection at 280 nm using a borate buffer containing sodium dodecyl sulfate (SDS). However, the metabolite of this drug (fenofibric acid) in serum and whole blood was analyzed by capillary zone electrophoresis (CZE) in a borate-carbonate buffer using acetonitrile stacking. The analysis is rapid, < 7 min with no interferences. Incubation of fenofibrate in whole blood caused hydrolysis of the ester bond with the release of fenofibric acid. PMID:15188253
Definition of performance specifications for automated Analytical Electrophoresis Facility (AAEF)
NASA Technical Reports Server (NTRS)
Brooks, D. E.
In order to provide specifications for the automated Analytical Electrophoresis Facility (AAEF) that would satisfy the broadest variety of demands of a future user community, a survey was carried out of all those people who were identified as having published papers on cell electrophoresis in the past four years. A computer search was conducted of the relevant literature from which a list of 87 investigators was derived and defined as the user community for purposes of the mailing. A questionnaire was developed covering the areas of performance which required definition which was subsequently circulated to the user community. Based on the response to this survey performance specifications were assembled.
Separation of DNA by free flow electrophoresis in space.
Kobayashi, H; Ishii, N
Free flow electrophoresis of a nematode C. elegans DNA was carried out on the space shuttle flight in International Microgravity Laboratory No. 2 (IML-2)., 1994. We selected the C. elegans DNA as the sample of the space experiment for free flow electrophoresis separation. This worm is a useful animal for the study of development and behavior by genetic analysis, and is a good candidate for a complete DNA sequence analysis because the haploid genome size consists of approximately 100 Mb (megabase) distributed on the six chromosomes, only 1/30 of human genome size. (Recently, the entire genomic DNA (97 Mb) sequences of C. elegans have been completed at the last December, 1998, as the first organism of multicellular system. In addition, many of the genes in C. elegans have extensive similarity to their mammalian counterparts. It may be possible to use the technology of free flow electrophoresis to contribute to the DNA analysis of the eukaryote. In this mission we attempted to make real-time communication between the space shuttle and on the ground during the electrophoresis processing. Because the separation tendency of the sample in space was not predicted so perfectly, the requests to the crews of the space shuttle was needed for selecting the fractions to be separated. According to the three dimensional electropherogram (3DEP) figured out the electrophoresis behavior, we were able to recover those fractions and kept in the deep freezer until landing. This real-time monitoring of the electrophoresis was the first evidence during space electrophoresis experiments which was started at Apollo 14, 1974. Unfortunately, some troubles occurred by contamination of bubbles in space nevertheless the post flight analyses of the fractionated samples were succeeded. The DNAs estimated by the DNA probes were not isolated one but the migration tendencies were differ from each other. It was clear that certain parts of the process in this study are advanced; that is, the precise monitoring of the electrophoresis process in space was accomplished, in real-time, by using 3DEP. In addition, the detection of DNA of recovered samples indicates that all the processes during the study were kept to be free from biological contamination. These results were published in following paper and reviewed in the book. PMID:11799254
Immunotoxicity of trenbolone acetate in Japanese quail
Quinn, M.J.; McKernan, M.; Lavoie, E.T.; Ottinger, M.A.
Trenbolone acetate is a synthetic androgen that is currently used as a growth promoter in many meat-exporting countries. Despite industry laboratories classifying trenbolone as nonteratogenic, data showed that embryonic exposure to this androgenic chemical altered development of the immune system in Japanese quail. Trenbolone is lipophilic, persistent, and released into the environment in manure used as soil fertilizer. This is the first study to date to assess this chemical's immunotoxic effects in an avian species. A one-time injection of trenbolone into yolks was administered to mimic maternal deposition, and subsequent effects on the development and function of the immune system were determined in chicks and adults. Development of the bursa of Fabricius, an organ responsible for development of the humoral arm of the immune system, was disrupted, as indicated by lower masse, and smaller and fewer follicles at day 1 of hatch. Morphological differences in the bursas persisted in adults, although no differences in either two measures of immune function were observed. Total numbers of circulating leukocytes were reduced and heterophil-lymphocyte ratios were elevated in chicks but not adults. This study shows that trenbolone acetate is teratogenic and immunotoxic in Japanese quail, and provides evidence that the quail immune system may be fairly resilient to embryonic endocrine-disrupting chemical-induced alterations following no further exposure posthatch.
[Ulipristal acetate, 5mg: a new alternative].
Monle�n Sancho, Javier; Romaguera, Eugenia; Romero, Ainhoa; Higueras, Gema; Morcillo, Inmaculada; Fuster, Sonia
Fibroids have a high prevalence (approaching 50%) in the female population. Although they are a benign entity, they represent a health problem of considerable magnitude, causing hemorrhaging, pain and sterility. Surgical treatment is currently safe and effective, but in recent decades numerous less invasive alternatives have appeared, such as uterine artery embolization and thermal ablation (HIFU and radiofrequency). New possibilities for medical treatment have also emerged, such as GnRh analogues, aromatase inhibitors and selective progesterone receptor modulators (SPRMs). SPRMs act through progesterone receptors and behave as agonists or antagonists in various target organs. Among them, ulipristal acetate (UA) inhibits the proliferation and induction of apoptosis and cell death pathways in leiomyoma cells, translating at the clinical level to smaller fibroids and lower uterine volumes, with no significant side effects. UA also produces amenorrhea in most patients. Randomized, phase III (PEARL I and II) clinical trials have shown the efficacy and security of UA versus placebo and leuprolide acetate (LA). UA is similar to LA, and superior to placebo in controlling bleeding and decreasing the size of the fibroid, with fewer side effects than LA. The safety and tolerance of UA have been satisfactory. UA is a reality in the preoperative treatment of fibroids, with broad potential for further development. PMID:24314567
Phytogenic biosynthesis and emission of methyl acetate.
Jardine, Kolby; Wegener, Frederik; Abrell, Leif; van Haren, Joost; Werner, Christiane
Acetylation of plant metabolites fundamentally changes their volatility, solubility and activity as semiochemicals. Here we present a new technique termed dynamic (13) C-pulse chasing to track the fate of C1-3 carbon atoms of pyruvate into the biosynthesis and emission of methyl acetate (MA) and CO2 . (13) C-labelling of MA and CO2 branch emissions respond within minutes to changes in (13) C-positionally labelled pyruvate solutions fed through the transpiration stream. Strong (13) C-labelling of MA emissions occurred only under pyruvate-2-(13) C and pyruvate-2,3-(13) C feeding, but not pyruvate-1-(13) C feeding. In contrast, strong (13) CO2 emissions were only observed under pyruvate-1-(13) C feeding. These results demonstrate that MA (and other volatile and non-volatile metabolites) derive from the C2,3 atoms of pyruvate while the C1 atom undergoes decarboxylation. The latter is a non-mitochondrial source of CO2 in the light generally not considered in studies of CO2 sources and sinks. Within a tropical rainforest mesocosm, we also observed atmospheric concentrations of MA up to 0.6 ppbv that tracked light and temperature conditions. Moreover, signals partially attributed to MA were observed in ambient air within and above a tropical rainforest in the Amazon. Our study highlights the potential importance of acetyl coenzyme A (CoA) biosynthesis as a source of acetate esters and CO2 to the atmosphere. PMID:23862653
Effect of iodination on human growth hormone and prolactin: characterized by bioassay, radioimmunoassay, radioreceptor assay, and electrophoresis
Hughes, J.P.; Tanaka, T.; Gout, P.W.; Beer, C.T.; Noble, R.L.; Friesen, H.G.
Human GH (hGH) and PRL (hPRL) were iodinated using lactoperoxidase. The iodinated hormones were characterized by RIA, radioreceptor assay (RRA), and bioassay (BA) using the Nb2 Node lymphoma cell line. The proportion of tracer that could bind to rat liver membranes or rabbit antibodies was determined, and the distribution of iodinated hormones was examined using polyacrylamide gel electrophoresis. Excess antibody was capable of precipitating 87.9% of the radioactivity associated with the hGH tracer and 86.0% of the hPRL tracer. The maximal specific binding to a liver membrane preparation averaged 67.3% of the (/sup 125/I)iodo-hGH radioactivity and 48.8% of the (/sup 125/I)iodo-hPRL radioactivity. The respective BA and RRA activity estimates for (/sup 125/I)iodo-hGH averaged 90% and 114% of the activity measured by the RIA. For (/sup 125/I)iodo-hPRL, the values were 75% by BA and 68% by RRA. The bioactivity profiles of iodinated hGH and hPRL shifted anodally on polyacrylamide gel electrophoresis in comparison to the bioactivity distribution of the respective uniodinated hormones. Iodine incorporation rather than oxidation appeared to be responsible for the shift. After electrophoresis, all eluates which contained significant radioactivity were active in the BA and RIA. Furthermore, specific activities calculated from the bioactive hormone and radioactivity in each electrophoretic segment agreed well with the average specific activity estimated from the amount of iodine incorporated into the protein peak upon gel filtration. These data suggest that hGH and hPRL to a major degree retain biological integrity after iodination.
Effect of iodination on human growth hormone and prolactin: characterized by bioassay, radioimmunoassay, radioreceptor assay, and electrophoresis
Hughes, J.P. (Univ. of Manitoba, Winnipeg, Canada); Tanaka, T.; Gout, P.W.; Beer, C.T.; Noble, R.L.; Friesen, H.G.
Human GH (hGH) and PRL (hPRL) were iodinated using lactoperoxidase. The iodinated hormones were characterized by RIA, radioreceptor assay (RRA), and bioassay (BA) using the Nb2 Node lymphoma cell line. The proportion of tracer that could bind to rat liver membranes or rabbit antibodies was determined, and the distribution of iodinated hormones was examined using polyacrylamide gel electrophoresis. Excess antibody was capable of precipitating 87.9% of the radioactivity associated with the hGH tracer and 86.0% of the hPRL tracer. The maximal specific binding to a liver membrane preparation averaged 67.3% of the (/sup 125/I)iodo-hGH radioactivity and 48.8% of the (/sup 125/I)iodo-hPRL radioactivity. The respective BA and RRA activity estimates for (/sup 125/)iodo-hGH averaged 90% and 114% of the activity measured by the RIA. For (/sup 125/I)iodo-hPRL, the values were 75% by BA and 68% by RRA. The bioactivity profiles of iodinated hGH and hPRL shifted anodally on polyacrylamide gel electrophoresis in comparison to the bioactivity distribution of the respective uniodinated hormones. Iodine incorporation rather than oxidation appeared to be responsible for the shift. After electrophoresis, all eluates which contained significant radioactivity were active in the BA and RIA. Furthermore, specific activities calculated from the bioactive hormone and radioactivity in each electrophoretic segment agreed well with the average specific activity estimated from the amount of iodine incorporated into the protein peak upon gel filtration. These data suggest that hGH and hPRL to a major degree retain biological integrity after iodination.
Acetate absorption and metabolism in the rabbit hindgut.
Marty, J F; Vernay, M Y; Abravanel, G M
Acetate disappearance from the loops of the hindgut in the rabbit was evaluated by measuring variations in the concentration of acetate in caecocolonic loops and differences in the arterial and venous plasma. In vivo metabolism in gut and liver tissues was studied after introduction of (1-14C) acetate into caecocolonic loops. The rate of disappearance from the loops was quantitatively significant and showed little variation irrespective of the location in the hindgut. Hindgut tissue metabolised acetate and the intensity of the metabolism varied with the segment studied. The distal position of the gut showed by far the highest acetate uptake. Radioactivity was found in a certain number of free amino acids, organic acids, and sugars. Acetate was mainly converted into aspartate and glutamate. These can be considered as 'stock forms' which can be diverted either towards oxidative metabolism or towards protein synthesis. Images Fig. 1 PMID:4007603
Buecker, B. [Kansas City Power and Light Co. (United States)
The Kansas Power and Light Co.'s La Cyne generating station has found success with membrane filtration water pretreatment technology. The article recounts the process followed in late 2004 to install a Pall Aria 4 microfilter in Unit 1 makeup water system at the plant to produce cleaner water for reverse osmosis feed. 2 figs., 2 photos.
Mesophilic syntrophic acetate oxidation during methane formation in biogas reactors
Anna Schn�rer; Gerhard Zellner; Bo H. Svensson
The reaction pathway for the formation of methane from acetate was investigated in sludge from 13 different biogas reactors. By following the conversion of [2-14C]acetate and [14C]bicarbonate it was shown that methane formation by syntrophic acetate oxidation was the dominating mechanism for acetotrophic methanogenesis in sludge containing high levels of salts, mainly ammonium, and volatile fatty acids. In one biogas
Solution behavior and surface properties of carboxymethylcellulose acetate butyrate
Jorge Amim Jr; Denise F. S. Petri; Francisco C. B. Maia; Paulo B. Miranda
Solution behavior of carboxymethylcellulose acetate butyrate (CMCAB) in acetone and ethyl acetate has been investigated by\\u000a small-angle X-ray scattering (SAXS) and capillary viscometry and correlated with the characteristics of CMCAB films. Viscosity\\u000a and SAXS measurements showed that ethyl acetate is a better solvent than acetone for CMCAB. Thin films of CMCAB were deposited\\u000a onto silicon wafers (Si\\/SiO2) by spin coating.
Monitoring neurochemical release from astrocytes using in vitro microdialysis coupled with high-speed capillary electrophoresis.
Hogerton, Amy L; Bowser, Michael T
We have developed a novel in vitro approach for monitoring fast neurochemical dynamics in model cell systems using microdialysis sampling coupled with high-speed capillary electrophoresis (CE). Cells from an immortalized astrocyte line (C8-D1A) were cultured in direct contact with the porous membrane of a microdialysis probe. Confocal microscopy was used to confirm cell viability and confluency over the microdialysis sampling region. Small molecules released from the astrocytes were efficiently sampled by the probe due to the direct contact with the membrane. Microdialysis sampling was coupled with online, high-speed CE allowing changes in the dialysate concentration of small molecule amine neurochemicals to be monitored with 20 s temporal resolution. Basal release of a number of important analytes was detected including glycine, taurine, D-serine, and glutamate. The ability of the in vitro microdialysis-CE instrument to monitor dynamic changes in analyte concentration was assessed by transferring a probe cultured with astrocytes from a solution containing artificial cerebrospinal fluid (aCSF) to a high K(+) solution (100 mM K(+)-aCSF). Upon stimulation, the observed concentration of a number of key neurochemicals increased dramatically including glycine (700%), taurine (185%), and serine (215%). Amino acids such as phenylalanine and valine, which are not known to respond to cellular swelling mechanisms, were unaffected by the K(+) stimulation. PMID:23984889
Assays for serum cholinesterase activity by capillary electrophoresis and an amperometric flow injection choline biosensor.
Hsieh, Bo-Chuan; Hsiao, Hsien-Yi; Cheng, Tzong-Jih; Chen, Richie L C
A capillary electrophoresis method and a durable choline biosensor were developed for measuring serum cholinesterase (EC 126.96.36.199) activity, a useful clinical index for liver function. The former is based on separation of benzoate and benzoylcholine (the artificial substrate of cholinesterase) in an uncoated fused-silica capillary. The migration time of benzoylcholine and benzoate was 1.3 min and 5.5 min, respectively. By the peak areas of A(233) signals, the linear dynamic ranges for both analytes were 0.01-50.0 mM, and the relative standard deviations of 1.0 mM benzoylcholine and benzoate were less than 4% and 6%, respectively. The FIA-choline sensor was constructed with the working electrode of the flow cell covered with a natural chitinous membrane purified from Taiwanese soldier crab, Mictyris brevidactylus. The biomembrane served as the supporting material for enzyme immobilization (choline oxidase, EC 184.108.40.206), and also prevented protein adsorption on the electrode surface. The calibration curve was linear between 0.05 and 5.0 mM (r=0.999). The relative standard deviations for 1.0 mM choline (n=7) were less than 3%, and the activity of the bioactive membrane lasted for about 2 months. The analytical results of both methods correlated well (r=0.940). PMID:18620919
Sorption and permeation behaviour of metal thiocyanate complexes on cellulose acetate polymers.
Hayashita, T; Takagi, M
Various metal thiocyanate complexes in aqueous solution were sorbed on solid cellulose acetate polymers. The sorption selectivity increased in the order Zn(2+) > Fe(3+) > Cu(2+) > Co(2+) > Ni(2+). The sorption behaviour followed a Langmuir-type adsorption isotherm, and the maximum adsorption capacity was 6.1 x 10(-5) mole of complex per g of polymer under optimum conditions. The zinc species sorbed appear to be NH(4)Zn(H(2)O)(SCN)(3) or (NH(4))(2)Zn(SCN)(4) according to analysis of the sorption equilibrium. The ion-association species formed by the complex zinc anion and the ammonium ion was supposed to be sorbed (or "extracted") onto the polymer matrix. As an application of sorption of metal complexes, a new hyperfiltration process was proposed for selective separation of metal ions. Thus, a mixture of metal thiocyanate complexes was hyperfiltered through cellulose acetate membranes. Permeation of certain metal complexes was preferred, and the selectivity was found to be similar to the sorption selectivity. These findings lead to a generalized idea that hyperfiltration separation of ionic species, particularly anionic metal complexes, can be attained by using polymer membranes which selectively adsorb or extract such ionic species as ion-association complexes onto the polymer matrix. PMID:18963867
Inter-relationship of sodium, chloride, bicarbonate and acetate transport by the colon of the pig.
Argenzio, R A; Whipp, S C
1. Net transport of Na, Cl, HCO3 and acetate was examined in the temporarily isolated colon of conscious pigs weighing 46 +/- 8 kg. 2. The entire colon absorbs 4.1 ml. H2O, 0.8 m-equiv Na, 1.3 m-equiv acetate and secretes 0.5 m-equiv HCO3/min with a solution comparable to the normal contents. The absorptive capacity of the proximal and distal halves of the colon was comparable per unit dry weight of mucosa when each segment was presented with the same solution. 3. A series of studies using ion replacement solutions showed that net Na absorption and net HCO3 accumulation in the lumen solution were both increased in the presence of acetate. Cl absorption was independent of Na absorption and was accompanied by an equivalent net secretion of HCO3 in the absence of Na. When NaCl in the perfusion solution was replaced with Na2SO4, Na and HCO3 were absorbed at equal rates. 4. Final pCO2 values observed in NaCl and Na2SO4 solutions were greater than those observed in plasma while the pCO2 of the Na acetate solution after perfusion was reduced to values below plasma concentrations. 5. Results are consistent with the hypothesis that hydration of CO2 in the lumen solution or mucosal cell provides a continuous source of H ions for absorption of the more permeable undissociated acid. The evidence also suggests an additional source of H ions may be provided by a Na-H exchange process located in one of the limiting cell membranes. PMID:42782
Negative Pressure Wound Therapy of Chronically Infected Wounds Using 1% Acetic Acid Irrigation
Lee, Byeong Ho; Lee, Hye Kyung; Kim, Hyoung Suk; Moon, Min Seon; Suh, In Suck
Background Negative-pressure wound therapy (NPWT) induces angiogenesis and collagen synthesis to promote tissue healing. Although acetic acid soaks normalize alkali wound conditions to raise tissue oxygen saturation and deconstruct the biofilms of chronic wounds, frequent dressing changes are required. Methods Combined use of NPWT and acetic acid irrigation was assessed in the treatment of chronic wounds, instilling acetic acid solution (1%) beneath polyurethane membranes twice daily for three weeks under continuous pressure (125 mm Hg). Clinical photographs, pH levels, cultures, and debrided fragments of wounds were obtained pre- and posttreatment. Tissue immunostaining (CD31, Ki-67, and CD45) and reverse transcription-polymerase chain reaction (vascular endothelial growth factor [VEGF], vascular endothelial growth factor receptor [VEGFR]; procollagen; hypoxia-inducible factor 1 alpha [HIF-1-alpha]; matrix metalloproteinase [MMP]-1,-3,-9; and tissue inhibitor of metalloproteinase [TIMP]) were also performed. Results Wound sizes tended to diminish with the combined therapy, accompanied by drops in wound pH (weakly acidic or neutral) and less evidence of infection. CD31 and Ki-67 immunostaining increased (P<0.05) post-treatment, as did the levels of VEGFR, procollagen, and MMP-1 (P<0.05), whereas the VEGF, HIF-1-alpha, and MMP-9/TIMP levels declined (P<0.05). Conclusions By combining acetic acid irrigation with negative-pressure dressings, both the pH and the size of chronic wounds can be reduced and infections be controlled. This approach may enhance angiogenesis and collagen synthesis in wounds, restoring the extracellular matrix. PMID:25606491
A capillary electrophoresis (CE) immunoassay format for 2,4-dichlorophenoxyacetic acid (2,4-D) is demonstrated. A fluorescent labeled 2,4-D analog competes with the analyte of interest for a finite number of binding sites provided by anti-2,4-D monoclonal antibodies. CE then pr...
Application of capillary electrophoresis in agricultural and soil chemistry research
Technology Transfer Automated Retrieval System (TEKTRAN)
As a modern analytical technique, capillary electrophoresis (CE) has become an attractive method for characterizing molecules wit high structural complexity and a wide range of molecular weights. CE can be used to analyze many natural chemical components such as acids, biogenic amines, peptides, pro...
Quantification of Polyacrylamide Gel Electrophoresis for Analysis of Whey Proteins
D. F. Darling; D. W. Butcher
Polyacrylamide gel electrophoresis of whey proteins has been quantified by standardization of the separation and staining procedure. During each electro- phoresis experiment, a standard solution of whey proteins was separated and stained under the same conditions as the test material. In this way, proteins in the standard solution were subjected to iden- tical processing conditions as the test samples. Densitometric
Measuring Genetic Variability in Natural Populations by Allozyme Electrophoresis
NSDL National Science Digital Library
James M. Bader (Case Western Reserve University; )
This resource provides a detailed introduction to the technique of gel electrophoresis as a means of analysing intra- and inter-population genetic variability. This exercise may be suited for incorporation with other laboratory or field experiments to provide additional information or a more synthetic framework.
Recent Progress in the Analysis of Pharmaceuticals by Capillary Electrophoresis
Theresa K. Natishan
Capillary electrophoresis is a powerful analytical technique which is increasing in utility in the pharmaceutical industry. It is used as an alternative or complementary technique to HPLC due to its high efficiency, speed of analysis, reduction in solvent and sample consumption, and low operating cost compared to HPLC methodology. Various modes have been developed and used for pharmaceutical analysis including
Separation of rat pituitary secretory granules by continuous flow electrophoresis
NASA Technical Reports Server (NTRS)
Hayes, Daniel; Exton, Carrie; Salada, Thomas; Shellenberger, Kathy; Waddle, Jenny; Hymer, W. C.
The separation of growth hormone-containing cytoplasmic secretory granules from the rat pituitary gland by continuous flow electrophoresis is described. The results are consistent with the hypothesis that granule subpopulations can be separated due to differences in surface charge; these, in turn, may be related to the oligomeric state of the hormone.
Electrophoresis 2012, 33, 599606 599 Rossella Gottardo1
Miksik, Ivan
-time of flight mass spectrometry (CZE-ESI-TOF MS) system. The effect of phosphate, borate and Tris buffers ammonium phosphate buffers showed good separation and ionization performances for all the analytes tested electrophoresis / Drugs of abuse / Non-volatile buffer / Phosphate / Time-of-flight mass spectrometry DOI 10
An Inexpensive Device for Capillary Electrophoresis with Fluorescence Detection
ERIC Educational Resources Information Center
Anderson, Greg; Thompson, Jonathan E.; Shurrush, Khriesto
We describe an inexpensive device for performing capillary electrophoresis (CE) separations with fluorescence detection. As a demonstration of the device's utility we have determined the mass of riboflavin in a commercially available dietary supplement. The device allows for separation of riboflavin in [asymptotically equivalent to] 100 s with a�
Polymerase Chain Reaction (PCR) and Gel Electrophoresis Powerpoint
NSDL National Science Digital Library
The HURI SURI project is developing a regional biotechnology workforce pipeline by expanding and supporting biotechnology research experiences for Jamestown Community College (JCC) undergraduates and disseminating these research experiences and materials to area high school teachers and students. This 15 slide presentation provides an introduction to DNA and explains polymerase chain reactions and gel electrophoresis. Many diagrams are included to help explain the concepts.
Silver Staining of 2D Electrophoresis Gels Thierry Rabilloud
Paris-Sud XI, Université de
Silver Staining of 2D Electrophoresis Gels Thierry Rabilloud CEA-DSV-iRTSV/LCBM and UMR CNRS separation on polyacrylamide gels. It combines excellent sensitivity (in the low nanogram range) with the use spectrometry, quantification, polyacrylamide gels, protein visualisation, silver staining #12;1. Introduction
Single cell gel electrophoresis assay: methodology and applications
E Rojas; M. C Lopez; M Valverde
The single cell gel electrophoresis or Comet assay is a sensitive, reliable, and rapid method for DNA double- and single-strand breaks, alkali-labile sites and delayed repair site detection, in eukariotic individual cells. Given its overall characteristics, this method has been widely used over the past few years in several different areas. In this paper we review the studies published to
Procedure for Mobility Gel Electrophoresis Prepare Linearized Plasmid DNA
Turro, Claudia
Procedure for Mobility Gel Electrophoresis Prepare Linearized Plasmid DNA 1. Purified pUC18 plasmid C (deactivating enzyme) 3. Follow with the gel extraction kit (it doubles as an enzymatic clean a Test Gel Gel Conditions 1. .75% agarose gel 2. TBE buffer (pH = 8.3) 3. 50 uM DNA 4. 10 mM Sodium
Temperature Effects on Electrophoresis Anita Rogacs and Juan G. Santiago*
Santiago, Juan G.
Temperature Effects on Electrophoresis Anita Rogacs and Juan G. Santiago* Department of Mechanical: We present a model capturing the important contributors to the effects of temperature on the observable electrophoretic mobilities of small ions, and on solution conductivity and pH. Our temperature
Gel Electrophoresis--The Easy Way for Students
ERIC Educational Resources Information Center
VanRooy, Wilhelmina; Sultana, Khalida
This article describes a simple, inexpensive, easy to conduct gel-electrophoresis activity using food dyes. It is an alternative to the more expensive counterparts which require agarose gel, DNA samples, purchased chamber and Tris-borate-EDTA buffer. We suggest some learning activities for senior biology students along with comments on several�
Electrostatic Stabilization of Colloids in Carbon Dioxide: Electrophoresis and Dielectrophoresis
Electrostatic Stabilization of Colloids in Carbon Dioxide: Electrophoresis and Dielectrophoresis in supercritical fluid carbon dioxide (scCO2). Herein we demonstrate that colloids may also be stabilized in CO2 the behavior of steric stabilization in compressed supercritical fluids1-3 including carbon dioxide,4
Quantitative Analysis of Human Milk Oligosaccharides by Capillary Electrophoresis
David S. Newburg; Zuojun Shen; Christopher D. Warren
Human milk oligosaccharides may have important biological activities. 1 We developed a sensitive, convenient, quantitative method for the routine study of sialylated (acidic, negatively charged) oligosaccharides in large numbers of milk samples. Capillary electrophoresis (CE) with detection at 205 nm was sensitive to the femtomole level and could resolve and quantify nine acidic oligosaccharides in milk, ranging from tri- to
Technology Transfer Automated Retrieval System (TEKTRAN)
High performance capillary electrophoresis (HPCE) is an analytical method that uses a voltage differential to accurately move solvents and solutes through a capillary. HPCE is a relative newcomer to the field of cereal chemistry, it utilizes small inner diameter capillaries as an anti-convective med...
Column Electrophoresis on the Apollo-Soyuz Test Project
Robert E. Allen; Percy H. Rhodes; Robert S. Snyder; Grant H. Barlow; Milan Bier; Pierluigi E. Bigazzi; Carel J. van Oss; Robert J. Knox; Geoffrey V. F. Seaman; Fortunato J. Micale; John W. Vanderhoff
Electrokinetic separation techniques have been widely used for the analysis and characterization of charged materials of biological origin. Under terrestrial conditions preparative methods based on zone electrophoresis, isotachophoresis, and isoelectric focusing are prominent in the purification of charged macromolecules and small particles but have only been of limited usefulness in the separation of biological cells and larger particles. The major
Solid friction in gel electrophoresis S. F. Burlatskya)
Deutch, John
Solid friction in gel electrophoresis S. F. Burlatskya) and John M. Deutch Department of Chemistry 1995 We study the influence of solid frictional forces acting on polymer chains moving in a random environment. We show that the total reduction in the chain tension resulting from the small friction between
Integral and peripheral association of proteins and protein complexes with Yersinia pestis inner and outer membranes
Rembert Pieper; Shih-Ting Huang; David J. Clark; Jeffrey M. Robinson; Hamid Alami; Prashanth P. Parmar; Moo-Jin Suh; Srilatha Kuntumalla; Christine L. Bunai; Robert D. Perry; Robert D. Fleischmann; Scott N. Peterson
Yersinia pestis proteins were sequentially extracted from crude membranes with a high salt buffer (2.5 M NaBr), an alkaline solution (180 mM Na2CO3, pH 11.3) and membrane denaturants (8 M urea, 2 M thiourea and 1% amidosulfobetaine-14). Separation of proteins by 2D gel electrophoresis was followed by identification of more than 600 gene products by MS. Data from differential 2D
Immunogold-localization and synthesis of an oil-body membrane protein in developing soybean seeds
Eliot M. Herman
The synthesis of a major oil-body membrane brotein was studied in maturing soybean (Glycine max (L.) Merr.) cotyledons. The membrane contained four abundant proteins with apparent molecular mass (Mr) of 34000, 24000, 18000 and 17000. The Mr=24000 protein (mP 24) was selected for more detailed analysis. The protein was purified to apparent homogeneity by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis
Water vapor diffusion membrane development
NASA Technical Reports Server (NTRS)
Tan, M. K.
An application of the water vapor diffusion technique is examined whereby the permeated water vapor is vented to space vacuum to alleviate on-board waste storage and provide supplemental cooling. The work reported herein deals primarily with the vapor diffusion-heat rejection (VD-HR) as it applies to the Space Shuttle. A stack configuration was selected, designed and fabricated. An asymmetric cellulose acetate membrane, used in reverse osmosis application was selected and a special spacer was designed to enhance mixing and promote mass transfer. A skid-mount unit was assembled from components used in the bench unit although no attempt was made to render it flight-suitable. The operating conditions of the VD-HR were examined and defined and a 60-day continuous test was carried out. The membranes performed very well throughout the test; no membrane rupture and no unusual flux decay was observed. In addition, a tentative design for a flight-suitable VD-HR unit was made.
An Investigation on Gel Electrophoresis with Quantum Dots End-labeled DNA
Chen, Xiaojia
Invented in the 1950s, gel electrophoresis has now become a routine analytical method to verify the size of nucleic acids and proteins in molecular biology labs. Conventional gel electrophoresis can successfully separate DNA fragments from several...
Abstract--This work addresses the segmentation of two-dimensional polyacrylamide gel electrophoresis images
Athens, University of
-PAGE Images, Overlapping Spots I. INTRODUCTION wo-dimensional polyacrylamide gel electrophoresis (2- D PAGEAbstract--This work addresses the segmentation of two- dimensional polyacrylamide gel electrophoresis images containing overlapping protein spots. A novel segmentation approach is proposed, which
Analysis of Bacterial Communities in Seagrass Bed Sediments by Double-Gradient Denaturing Gradient Gel Electrophoresis
Sherman, Tim
-Gradient Denaturing Gradient Gel Electrophoresis of PCR-Amplified 16S rRNA Genes J.B. James1 , T.D. Sherman2 and R denaturing gradient gel electrophoresis (DG- DGGE) was used to generate banding patterns from
Ulipristal acetate: a new emergency contraceptive.
Sullivan, Jade L; Bulloch, Marilyn N
Ulipristal acetate (UPA) is a newly developed emergency contraceptive currently available in the USA and Europe. It is approved as a 30 mg one-time dose taken within 120 h (5 days) of unprotected intercourse or failed contraception. This selective progesterone receptor modulator appears to be more effective than the levonorgestrel-containing emergency contraceptive, which must be taken within 72 h of unprotected intercourse. According to pharmacodynamic trials, UPA delays follicular maturation and ovulation. In addition, UPA may modulate the endometrium. Both Phase III clinical trials found that UPA does not lose efficacy within the 120-h dosing interval. Throughout all phases of clinical studies, UPA was shown to be well tolerated with only minimal adverse drug reactions, all of which are similar to competitor therapies. PMID:22114852
Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by an enzyme preparation from Zea mays
NASA Technical Reports Server (NTRS)
Reinecke, D. M.; Bandurski, R. S.
Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity. A heat-stable, detergent-extractable component from corn enhances enzyme activity 6- to 10-fold. This is the first demonstration of the in vitro enzymic oxidation of indole-3-acetic acid to oxindole-3-acetic acid in higher plants.
Development of a useful technique to discriminate anterior cruciate ligament cells and mesenchymal stem cells--the application of cell electrophoresis.
Lee, I-Chi; Wang, Jyh-Horng; Lee, Yu-Tsang; Young, Tai-Horng
Mesenchymal stem cells (MSCs) can differentiate into multiple nonhematopoietic cell lineages, including osteoblasts, chondrocytes, and ligament cells. The purpose of this study is to identify the difference between MSCs and anterior cruciate ligament (ACL) cells for the application of distinguishing these two cells during the process of MSCs differentiating into ACL cells. Although culture of MSCs and ACL cells have been studied extensively, it was found that these two cells could not be distinguished from their appearance, expression of surface antigens (including CD105, CD34, CD45, CD29, CD44, and CD71), alpha-smooth muscle actin, and mRNAs for type I collagen, type III collagen, and tenascin-C, based on a series of traditional methods for cell identification. Cell electrophoresis, measuring the electrophoretic mobility (EPM) of cells, was proposed to investigate the discrepancy in surface charge properties of MSCs and ACL cells. Surprisingly, the EPM value of MSCs is significantly greater than that of ACL cells (p < 0.001). Although cell electrophoresis cannot determine the specific surface protein, it can reflect the net surface charge density of cell membrane, which can be influenced by the dissociation of functional groups of peripheral membrane proteins. Therefore, it is suggested that cell electrophoresis, while simple and cheap in manipulation, can serve as a useful research tool to assist in identification of MSCs differentiating into ACL cells. PMID:17266022
Antitumor and apoptotic activities of the chemical constituents from the ethyl acetate extract of Artemisia indica.
Zeng, Ying-Tong; Jiang, Jian-Min; Lao, Hai-Yan; Guo, Jie-Wen; Lun, Yu-Ning; Yang, Min
Cancer is one of the most eminent diseases of modern times and numerous natural products derived from medicinal plants have been identified as potential sources of antitumor drugs. A successful anticancer drug must target or inhibit tumor cells whilst causing minimal damage to healthy cells. The present study aimed to investigate the antitumor efficacy of ethyl acetate extract, and other isolated compounds from Artemisia indica, on MCF?7, BHY, Miapaca?2, Colo?205 and A?549 cell lines. The apoptotic activity of the compounds was studied using flow cytometry. The different cancer cell lines were treated with the ethyl acetate extract and varying concentrations of compounds (denoted a?g) isolated from the A. indica. The cytotoxicity was evaluated by MTT assay and the apoptotic properties of the compounds and the extract were assessed using flow cytometry. In MCF?7 cells, the effect on mitochondrial membrane potential loss (??m) induced by compounds b and d was also studied. Bioassay?guided fractionation of the ethyl acetate extract from the shoot and root parts of A. indica led to the identification of the compounds a?g as: 5?hydroxy?3,7,4'?trimethoxyflavone; ludartin; maackiain; lupeol; cis?matricaria ester; trans?matricaria ester; and 6?methoxy?7,8?methylenedioxy coumarin, respectively. All the compounds exhibited mild to potent inhibition of cell proliferation in all the cell lines, with the half maximal inhibitory concentration values ranging from 25.18?88.12 �M. Ludartin and lupeol were observed to have the most potent inhibitory effects. Based on the initially identified antiproliferative effects, these two compounds were evaluated for their effects on cell cycle phase distribution, DNA damage and their effects on mitochondrial membrane potential loss (??m). The two compounds induced DNA damage and mitochondrial membrane potential loss in MCF?7 cells. The results of the current study suggest that lupeol and ludartin, isolated from A. indica, produce anticancer effects by inducing DNA damage and a reduction of mitochondrial membrane potential, and may be used as potent anticancer agents, subsequent to further study. PMID:25434991
Effect of different carbon sources on membrane permeability, membrane fluidity, and fatty acid composition of a psychrotrophic Acinetobacter sp. HH1-1 during growth at low temperatures and after cold shock
S. E. Barbaro; J. T. Trevors; W. E. Inniss
The effect of different carbon sources on the ability of a psychrotrophic Acinetobacter sp., strain HH1-1, to grow at low temperatures and respond to cold shock was investigated by monitoring cell membrane permeability, membrane fluidity and fatty acid composition. Cells were grown in batch cultures with acetate, Tween 80 or olive oil as the sole source of carbon and incubated
Heterogeneous catalyst for the production of acetic anhydride from methyl acetate
Ramprasad, Dorai (Allentown, PA); Waller, Francis Joseph (Allentown, PA)
This invention relates to a process for producing acetic anhydride by the reaction of methyl acetate, carbon monoxide, and hydrogen at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that contains an insoluble polymer having pendant quaternized phosphine groups, some of which phosphine groups are ionically bonded to anionic Group VIII metal complexes, the remainder of the phosphine groups being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for consecutive runs without loss in activity. Bifunctional catalysts for use in carbonylating dimethyl ether are also provided.
Heterogeneous catalyst for the production of acetic anhydride from methyl acetate
Ramprasad, D.; Waller, F.J.
This invention relates to a process for producing acetic anhydride by the reaction of methyl acetate, carbon monoxide, and hydrogen at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that contains an insoluble polymer having pendant quaternized phosphine groups, some of which phosphine groups are ionically bonded to anionic Group VIII metal complexes, the remainder of the phosphine groups being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for consecutive runs without loss in activity. Bifunctional catalysts for use in carbonylating dimethyl ether are also provided.
Effect of membrane characteristics on the performance of membrane bioreactors for oily wastewater treatment.
Mafirad, S; Mehrnia, M R; Sarrafzadeh, M H
Influence of membrane material and pore size on the performance of a submerged membrane bioreactor (sMBR) for oily wastewater treatment was investigated. The sMBR had a working volume of about 19 L with flat sheet modules at the same hydrodynamic conditions. Five types of micro- and ultra-polymeric membranes containing cellulose acetate (CA), cellulose nitrate (CN), polyamide (PA), polyvinylidene difluoride (PVDF) and polyethersulfone (PES) were used and their filtration performance in terms of permeability, permeate quality and fouling intensity were evaluated. Characterization of the membranes was done by performing some analysis such as pore size distribution; contact angle and scanning electronic microscopy (SEM) microphotograph on all membranes. The quality of permeates from each membrane was identified by measuring chemical oxygen demand (COD). The results showed more irreversible fouling intensity for membranes with larger pore size which can be due to more permeation of bioparticles and colloids inside the pores. Membrane characteristics have a major role in the preliminary time of the filtration before cake layer formation so that the PA with the highest hydrophilicity had the lowest permeability decline by fouling in this period. Also, the PVDF and PES membranes had better performance according to better permeate quality in the preliminary time of the filtration related to smaller pore size and also their better fouling resistance and chemical stability properties. However, all membranes resulted in the same permeability and permeate quality after cake layer formation. An overall efficiency of about 95% in COD removal was obtained for oily wastewater treatment by the membranes used in this study. PMID:22214065
Profiling Solid-Phase Synthesis Products by Free-Solution Conjugate Capillary Electrophoresis
Barron, Annelise E.
Profiling Solid-Phase Synthesis Products by Free-Solution Conjugate Capillary Electrophoresis Wyatt. In this report, we apply this bioconjugate capillary electrophoresis technique to analyze products of the solid. With the advent of capillary array electrophoresis (CAE), which allows for automated, parallel analysis of many
Polymer Preprints 2000, 41(1), 1018 FREE-SOLUTION CAPILLARY ELECTROPHORESIS OF
Barron, Annelise E.
Polymer Preprints 2000, 41(1), 1018 FREE-SOLUTION CAPILLARY ELECTROPHORESIS OF POLYPEPTOID capillary electrophoresis is the introduction of the polymeric sieving matrix into the small lumen of the capillary 1 . As instrumentation is further miniaturized, as in electrophoresis chips, loading a replaceable
DNA Sequencing up to 1300 Bases in Two Hours by Capillary Electrophoresis with Mixed
Barron, Annelise E.
DNA Sequencing up to 1300 Bases in Two Hours by Capillary Electrophoresis with Mixed Replaceable separation times using capillary electrophoresis with replaceable polymer ma- trixes. In previous work on capillary array electrophoresis with replaceable polymer solutions. DNA sequencing remains the gold standard
DETECTION AND SEGMENTATION IN 2D GEL ELECTROPHORESIS IMAGES Eirini Kostopoulou, Eleni Zacharia, and Dimitris Maroulis
Athens, University of
DETECTION AND SEGMENTATION IN 2D GEL ELECTROPHORESIS IMAGES Eirini Kostopoulou, Eleni Zacharia: firstname.lastname@example.com, firstname.lastname@example.com, firstname.lastname@example.com ABSTRACT Analyzing 2D-gel electrophoresis presents an original approach to detecting and segmenting spots in 2D-gel electrophoresis images
A statistical model for unwarping of 1-D electrophoresis C.A. Glasbey
Stone, J. V.
A statistical model for unwarping of 1-D electrophoresis gels C.A. Glasbey Biomathematics, which relates density profiles in 1-D electrophoresis gels, such as those produced by pulsed-field gel electrophoresis (PFGE), to databases of profiles of known genotypes. The warp in each gel lane is described
Unsupervised 2D gel electrophoresis image segmentation based on active contours
Athens, University of
Unsupervised 2D gel electrophoresis image segmentation based on active contours Michalis A August 2011 Keywords: Segmentation Active contours 2D-gel electrophoresis images a b s t r a c in two-dimensional gel electrophoresis (2D-GE) images. The proposed segmentation scheme is the first
A Spot Segmentation Approach for 2D Gel Electrophoresis Images Based on 2D Histograms
Athens, University of
A Spot Segmentation Approach for 2D Gel Electrophoresis Images Based on 2D Histograms firstname.lastname@example.com Abstract Spot-Segmentation, an essential stage of processing 2D gel electrophoresis images, remains approach to spot segmentation in 2D gel electrophoresis images. The proposed approach is based on 2D
GEL ELECTROPHORESIS 2009 1 Minority Science Programs School of Biological Sciences University of California, Irvine
Rose, Michael R.
GEL ELECTROPHORESIS 2009 1 Minority Science Programs School the DNA encodes just by looking at the tube. Gel electrophoresis is one of the techniques scientists use to look at the DNA they have. This technique separates DNA molecules by size. How gel electrophoresis
Segmentation of 2D Gel Electrophoresis Spots Using a Markov Random Field
Corso, Jason J.
Segmentation of 2D Gel Electrophoresis Spots Using a Markov Random Field Christopher S. Hoeflich based model was tested on actual 2D gel electrophoresis images. Keywords: Segmentation, Statistical) model and simulated annealing. The entire process of matching 2D gel electrophoresis images is widely