biuret test is used to test the presence of
peptide bonds
7560016
the Polish toxological chemist, Jerzy Kazimierz Piotrowski (b. 1926) of Lodz. Biuret test The biuret test (Piotrowski's test) is a chemical test used for detecting the presence of peptide bonds. In the presence of peptides, a copper(II) ion forms mauve-colored coordination complexes in an alkaline solution. Several variants on the test have been developed, such as the BCA test and the Modified Lowry test. The biuret reaction can be used to assess the concentration of proteins because peptide bonds occur with the same frequency per amino acid in the peptide. The intensity of the color, and hence the absorption at
Biuret test
7560010
Biuret test The biuret test (Piotrowski's test) is a chemical test used for detecting the presence of peptide bonds. In the presence of peptides, a copper(II) ion forms mauve-colored coordination complexes in an alkaline solution. Several variants on the test have been developed, such as the BCA test and the Modified Lowry test. The biuret reaction can be used to assess the concentration of proteins because peptide bonds occur with the same frequency per amino acid in the peptide. The intensity of the color, and hence the absorption at 540 nm, is directly proportional to the protein concentration, according to
Biuret test
7560016
the Polish toxological chemist, Jerzy Kazimierz Piotrowski (b. 1926) of Lodz. Biuret test The biuret test (Piotrowski's test) is a chemical test used for detecting the presence of peptide bonds. In the presence of peptides, a copper(II) ion forms mauve-colored coordination complexes in an alkaline solution. Several variants on the test have been developed, such as the BCA test and the Modified Lowry test. The biuret reaction can be used to assess the concentration of proteins because peptide bonds occur with the same frequency per amino acid in the peptide. The intensity of the color, and hence the absorption at
Biuret test
6132600
characteristic also slows down its digestion and so decreases the risk of ammonia toxicity. The biuret test is a chemical test for proteins and polypeptides. It is based on the biuret reagent, a blue solution that turns violet upon contact with proteins, or any substance with peptide bonds. The test and reagent do not actually contain biuret; they are so named because both biuret and proteins have the same response to the test. Biuret Biuret is a chemical compound with the chemical formula CHNO. It is also known as carbamylurea. It is the result of condensation of two molecules of
Biuret
7560013
cupric ions. The reaction of the cupric ions with the nitrogen atoms involved in peptide bonds leads to the displacement of the peptide hydrogen atoms under the alkaline conditions. A tri- or tetra-dentate chelation with the peptide nitrogen produces the characteristic color. This is found with dipeptides (Datta, S.P., Leberman, R., and Rabin, B.R., Trans.Farad.Soc. (1959), 55, 2141). The reagent is commonly used in the biuret protein assay, a colorimetric test used to determine protein concentration by UV/VIS spectroscopy at wavelength 540 nm. Two major modifications of the biuret test are commonly applied in modern colorimetric analysis of peptides: the
Biuret test
12424157
Millon's reagent Millon's reagent is an analytical reagent used to detect the presence of soluble proteins. A few drops of the reagent are added to the test solution, which is then heated gently. A reddish-brown coloration or precipitate indicates the presence of tyrosine residue which occur in nearly all proteins. Millon's test is not specific for proteins (it detects phenolic compounds), and so must be confirmed by other tests for proteins such as the biuret test and the ninhydrin reaction. The reagent is made by dissolving metallic mercury in nitric acid and diluting with water. The test was developed by
Millon's reagent
12424158
the French chemist Auguste Nicolas Eugene Millon (1812–1867). Millon's reagent Millon's reagent is an analytical reagent used to detect the presence of soluble proteins. A few drops of the reagent are added to the test solution, which is then heated gently. A reddish-brown coloration or precipitate indicates the presence of tyrosine residue which occur in nearly all proteins. Millon's test is not specific for proteins (it detects phenolic compounds), and so must be confirmed by other tests for proteins such as the biuret test and the ninhydrin reaction. The reagent is made by dissolving metallic mercury in nitric acid and
Millon's reagent
7560014
bicinchoninic acid (BCA) assay and the Lowry assay. In these tests, the Cu formed during the biuret reaction reacts further with other reagents, leading to a deeper color. In the BCA test, Cu forms a deep purple complex with bicinchoninic acid (BCA), which absorbs around 562 nm, producing the signature mauve color. The water-soluble BCA/copper complex absorbs much more strongly than the peptide/copper complex, increasing the sensitivity of the biuret test by a factor of around 100: the BCA assay allows to detect proteins in the range of 0.0005 to 2 mg/mL). Additionally, the BCA protein assay gives the important
Biuret test
7560011
the Beer–Lambert law. Despite its name, the reagent does not in fact contain biuret ((HN-CO-)NH). The test is named so because it also gives a positive reaction to the peptide-like bonds in the biuret molecule. In this assay, the copper(II) binds with nitrogens present in the peptides of proteins. In a secondary reaction, the copper(II) is reduced to copper(I). Buffers, such as Tris and ammonia interfere with this assay, therefore rendering this assay inappropriate for protein samples purified from ammonium sulfate precipitation. Due to its insensitivity and little interference by free amino acids, this assay is most useful for whole
Biuret test
2673051
remove snails from aquariums. Copper ions are highly toxic to fish, however. Most species of algae can be controlled with very low concentrations of copper sulfate. Several chemical tests utilize copper sulfate. It is used in Fehling's solution and Benedict's solution to test for reducing sugars, which reduce the soluble blue copper(II) sulfate to insoluble red copper(I) oxide. Copper(II) sulfate is also used in the Biuret reagent to test for proteins. Copper sulfate is used to test blood for anemia. The blood is tested by dropping it into a solution of copper sulfate of known specific gravity – blood which
Copper(II) sulfate
7560015
benefit of compatibility with substances such as up to 5% surfactants in protein samples. In the Lowry protein assay Cu is oxidized back to Cu by Mo in Folin-Ciocalteu's reagent, which forms molybdenum blue (Mo). Tyrosine residues in the protein also form molybdenum blue under these circumstances. In this way, proteins can be detected in concentrations between 0.005 and 2 mg/mL. Molybdenum blue in turn can bind certain organic dyes such as malachite green and Auramine O, resulting in further amplification of the signal. In Poland, the Biuret Test is more commonly called as the "Piotrowski Test", in honor of
Biuret test
13221552
In Molisch's test, 1-naphthol dissolved in ethanol, known as Molisch's reagent, is used as reagent for detecting the presence of carbohydrates. The test known as Molisch's test would give a red- or purple-colored compound to indicate the presence of carbohydrate. The rapid furfural test, similar to Molisch's test, also uses 1-naphthol. The Sakaguchi test uses 1-naphthol with sodium hypobromite to detect the presence of arginine in proteins. The Voges–Proskauer test uses 1-naphthol in potassium hydroxide (KOH) solution to detect the breakdown of glucose into acetoin which is used by bacteria for external energy storage. A positive test will be indicated
1-Naphthol
8257992
Serum total protein Serum total protein, also known as total protein, is a biochemical test for measuring the total amount of protein in serum. Protein in the serum is made up of albumin and globulin. The globulin in turn is made up of α1, α2, β, and γ globulins. These fractions can be quantitated using protein electrophoresis, but the total protein test is a faster and cheaper test that estimates the total of all fractions together. The traditional method for measuring total protein uses the biuret reagent, but other chemical methods such as Kjeldahl method, dye-binding and refractometry are now
Serum total protein
17539301
Substantial Presence Test The Substantial Presence Test (SPT) is a criterion used by the Internal Revenue Service (IRS) in the United States to determine whether an individual who is "not" a citizen or lawful permanent resident in the recent past qualifies as a "resident for tax purposes" or a "nonresident for tax purposes"; it is a form of physical presence test. The SPT should be used in conjunction with the Green Card Test (the criterion that the individual possessed a valid Green Card at any time of the year). An individual who satisfies either one or both of these tests
Substantial Presence Test
7560012
tissue samples and other sources with high protein concentration. An aqueous sample is treated with an equal volume of 1% strong base (sodium or potassium hydroxide) followed by a few drops of aqueous copper(II) sulfate. If the solution turns purple, protein is present. 5–160 mg/mL can be determined. Peptides with the correct length of at least 3 amino acids are necessary for a significant, measurable colour shift with these reagents. The Biuret reagent is made of sodium hydroxide (NaOH) and hydrated copper(II) sulfate, together with potassium sodium tartrate, the latter of which is added to chelate and thus stabilize the
Biuret test
17539313
being otherwise dual-status. Substantial Presence Test The Substantial Presence Test (SPT) is a criterion used by the Internal Revenue Service (IRS) in the United States to determine whether an individual who is "not" a citizen or lawful permanent resident in the recent past qualifies as a "resident for tax purposes" or a "nonresident for tax purposes"; it is a form of physical presence test. The SPT should be used in conjunction with the Green Card Test (the criterion that the individual possessed a valid Green Card at any time of the year). An individual who satisfies either one or both
Substantial Presence Test
1550146
a negative test. Benedict's reagent can be used to test for the presence of glucose in urine. Glucose in urine is called glucosuria and can be indicative of diabetes mellitus, but the test is not recommended or used for the diagnosis of diabetes mellitus. A false positive reaction can be due to the presence of other reducing substances in urine such as ascorbic acid (during intake of vitamin supplements), drugs (levodopa, contrast used in radiological procedures) and homogentisic acid (alkaptonuria). Benedict's solution is a deep-blue solution used to test for the presence of the aldehyde functional group, - CHO. It
Benedict's reagent
17963877
Gmelin's test Gmelin's test is a chemical test used for detecting the presence of bile pigments in urine. It is named after Leopold Gmelin, who introduced the test. Five millilitres of urine is slowly added to five millilitres of concentrated nitric acid in a test-tube. Different coloured rings between the two layers are visible if bile pigments are present as they are oxidised to various chemical products. Nitric acid is used as the oxidising agent. Blue, green and violet rings are seen if bilirubin is present. Gmelin's test is not sensitive so a positive result always indicates the presence of
Gmelin's test
6789742
to determine if the bleeding is from the mother or the fetus. In practice, the Apt test may not be done when there is suspicion of vasa previa, because the time to fetal collapse with bleeding from vasa previa is often very short. The Apt test can also be used to detect the presence of fetal blood in the maternal circulation in cases of suspected fetal-maternal hemorrhage. Since the test is only a qualitative determination of the presence of fetal hemoglobin in maternal blood, the quantitative Kleihauer-Betke test is more commonly used. Finally, the Apt test can be used after
Alkali denaturation test
17963878
bile pigments but a negative result does not exclude the presence of small quantities of bile pigments. Gmelin's test Gmelin's test is a chemical test used for detecting the presence of bile pigments in urine. It is named after Leopold Gmelin, who introduced the test. Five millilitres of urine is slowly added to five millilitres of concentrated nitric acid in a test-tube. Different coloured rings between the two layers are visible if bile pigments are present as they are oxidised to various chemical products. Nitric acid is used as the oxidising agent. Blue, green and violet rings are seen if
Gmelin's test
6482604
Test light A test light, test lamp, voltage tester, or mains tester is a piece of electronic test equipment used to determine the presence of electricity in a piece of equipment under test. A test light is simpler and less costly than a measuring instrument such as a multimeter, and often suffices for checking for the presence of voltage on a conductor. Properly designed test lights include features to protect the user from accidental electric shock. Non-contact test lights can detect voltage on insulated conductors. The test light is an electric lamp connected with one or two insulated wire leads.
Test light
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Physical presence test In international taxation, a physical presence test is a rule used to determine tax residence of a natural or legal person. It may rely on having a place of business in the jurisdiction (for legal persons), or remaining in or out of the jurisdiction for a certain number of days each year (for natural persons). The "physical presence in Australia test" is one of the three tests under Australian law through which a charitable institution may be entitled to the income tax exempt charity endorsement; the others are the "deductible gift recipient test" and the "prescribed by
Physical presence test
7407240
Leukocyte esterase Leukocyte esterase (LE) is an esterase (a type of enzyme) produced by leukocytes (white blood cells). A leukocyte esterase test (LE test) is a urine test for the presence of white blood cells and other abnormalities associated with infection. White blood cells in the urine usually indicate a urinary tract infection (UTI). Positive test results are clinically significant. The LE test is also used to screen for gonorrhea and for amniotic fluid infections. The combination of the LE test with the urinary nitrite test provides an excellent screen for establishing the presence of a UTI. Urine test strips
Leukocyte esterase
15810302
Jonas Kamlet Jonas Kamlet, Ph. D. (1914 – December 16, 1960) was an inventor, chemist, and a successful entrepreneur. He founded Kamlet Chemical Laboratories in New York City. He invented a glucose test using a tablet to measure the amount of glucose in urine, a treated strip that could identify pregnancy, a fodder for ruminants that used newsprint, synthesis of biuret that could be used as an element of fodder along with hundreds of other patents. His wife, Edna Yadven Kamlet Rogers, assisted him in the activities of the Kamlet Laboratories. She was a resident of Sarasota, Florida and had
Jonas Kamlet
15810311
The Kamlet Collection documents fundamental chemistry achievements starting in 1940 and ending in the mid 1960s. They serve as a beneficial resource for generations of chemistry students. Jonas Kamlet Jonas Kamlet, Ph. D. (1914 – December 16, 1960) was an inventor, chemist, and a successful entrepreneur. He founded Kamlet Chemical Laboratories in New York City. He invented a glucose test using a tablet to measure the amount of glucose in urine, a treated strip that could identify pregnancy, a fodder for ruminants that used newsprint, synthesis of biuret that could be used as an element of fodder along with hundreds
Jonas Kamlet
7737351
Nitrite test A nitrite test is a chemical test used to determine the presence of nitrite ion in solution. A common nitrite test can be performed by adding 4 M sulfuric acid to the sample until acidic, and then adding 0.1 M iron(II) sulfate to the solution. A positive test for nitrite is indicated by a dark brown solution, arising from the iron-nitric oxide complex ion. A nitrite test is a standard component of a urinary test strip. A positive test for nitrites in the urine is called nitrituria. This test is commonly used in diagnosing urinary tract infections (UTIs).
Nitrite test
15938264
Fern test Fern test refers to detection of a characteristic 'fern like' pattern of cervical mucus when a specimen of cervical mucus is allowed to dry on a glass slide and is viewed under a low-power microscope. The fern test is used to provide evidence of the presence of amniotic fluid and is used in obstetrics to detect the rupture of membranes and the onset of labor. It also may provide indirect evidence of ovulation and fertility, although it does not predict the time of ovulation. Ferning occurs due to the presence of sodium chloride in mucus under estrogen effect.
Fern test
18352816
Bagolini Striated Glasses Test Bagolini striated glasses test, or BSGT, is a subjective clinical test to detect the presence or extent of binocular functions and is generally performed by an Optometrist(O.D) or orthoptist or ophthalmologist (medical/surgical eye doctor, M.D. or D.O.). It is mainly used in strabismus clinics. Through this test, suppression, microtropia, diplopia and manifest deviations can be noted. However this test should always be used in conjunction with other clinical tests, such as Worth 4 dot test, Cover test, Prism cover test and Maddox rod to come to a diagnosis. To perform the test you will need Alternatively,
Bagolini Striated Glasses Test
13326186
or surface of the fluorescence area indicate the presence of corneal leakage. If the fluorescein strip turns pale upon application to the corneal surface, the person tests positive for the corneal deformity he/ she is being tested for. The change in the color of the fluorescein strip is due to dilution of fluorescein caused by the aqueous leakage in the cornea. Seidel test The Seidel Test is used to assess the presence of anterior chamber leakage in the cornea. It is used as a screening test for many corneal disorders including corneal post-trauma, corneal perforation and corneal degeneration. The Seidel
Seidel test
8473864
use tax on Quill, which was struck down by the Supreme Court, because Quill had no physical presence in North Dakota. The "Quill" physical presence test is used by some states to determine whether or not a company must pay franchise tax. Delaware, Hawaii, Massachusetts, Pennsylvania, and Texas report using the physical presence test. Many states apply an "economic presence" test to determine whether a business will be subject to state sales or franchise tax. This test, which seems to contradict Quill, implied that States have the right to tax or "nexus" solely on the basis that a company has
Franchise tax
6325955
Bead test The bead test is a traditional part of qualitative inorganic analysis to test for the presence of certain metals. The oldest one is the borax bead test or blister test. It was introduced by Berzelius in 1812. Since then other salts were used as fluxing agents, such as sodium carbonate or sodium fluoride. The most important one after borax is microcosmic salt, which is the basis of the microcosmic salt bead test. A small loop is made in the end of a platinum or Nichrome wire is (as used in the flame test) (or another inert substance like
Bead test
13367372
Trinder glucose activity test The Trinder glucose activity test is a diagnostic test used in medicine to determine the presence of glucose or glucose oxidase. The test employs the Trinder reagent, and is a colour change test resulting from the Trinder reaction. The Trinder reagent, named after P. Trinder of the Biochemistry Department of the Royal Infirmary in Sunderland (see the article listed in further reading), comprises an aminoantipyrine (such as 4-aminoantipyrine) and phenol (p-hydroxybenzene). The Trinder reaction is the reaction between hydrogen peroxide and the phenol and aminoantipyrine to form a quinone (quinoneimine), catalyzed by the presence of a
Trinder glucose activity test
17890455
Yergason's test Yergason's test is a special test used for orthopedic examination of the shoulder and upper arm region, specifically the biceps tendon. It identifies the presence of a pathology involving the biceps tendon or glenoid labrum. The specific positive findings to the test include: pain in the bicipital groove indicating biceps tendinitis, subluxation of the long head of the biceps brachii muscle, and presence of a SLAP tear. Palpating the biceps tendon as it passes through the bicipital groove to identify any lesions, abnormal bumps, or abnormal movement (i.e. biceps tendon) in the involved area. To perform the test,
Yergason's test
7737343
nitrogen dioxide. Nitrate test A nitrate test is a chemical test used to determine the presence of nitrate ion in solution. Testing for the presence of nitrate via wet chemistry is generally difficult compared with testing for other anions, as almost all nitrates are soluble in water. In contrast, many common ions give insoluble salts, e.g. halides precipitate with silver, and sulphate precipitate with barium. The nitrate anion is an oxidizer, and many tests for the nitrate anion are based on this property. Unfortunately, other oxidants present in the analyte may interfere and give erroneous results. A common nitrate test,
Nitrate test
7737339
Nitrate test A nitrate test is a chemical test used to determine the presence of nitrate ion in solution. Testing for the presence of nitrate via wet chemistry is generally difficult compared with testing for other anions, as almost all nitrates are soluble in water. In contrast, many common ions give insoluble salts, e.g. halides precipitate with silver, and sulphate precipitate with barium. The nitrate anion is an oxidizer, and many tests for the nitrate anion are based on this property. Unfortunately, other oxidants present in the analyte may interfere and give erroneous results. A common nitrate test, known as
Nitrate test
13101226
After incubation for 24 hours at 37 degrees Celsius, plates are examined with transmitted light for the presence of fine precipitin lines at a 45-degree angle to the streaks. The presence of precipitin lines indicates that the strain produced toxin that reacted with the antitoxin. Elek's test Elek's test, also known as the immunodiffusion technique, is an "in vitro" virulence test performed upon "Corynebacterium diphtheriae". It is used to test for toxigenicity of "C. diphtheriae". It was characterized in 1949 by American microbiologist Stephen Dyonis Elek (1914–1992). A strip of filter paper impregnated with diphtheria antitoxin is buried just beneath
Elek's test
2227524
to 4 weeks. This test is not done on spinal fluid. The MHA-TP test is rarely used any more. Treponema pallidum particle agglutination assay (TP-PA), and the Toluidine red unheated serum test (TRUST) which may be used to confirm a positive VDRL result. These tests are more specific for syphilis than non-treponemal tests and, in the presence of a positive test, more likely indicate active infection. Unfortunately other treponemal infections such as yaws, bejel and pinta and possibly nonpathogenic commensal treponemes can result in a positive. Venereal Disease Research Laboratory test The Venereal Disease Research Laboratory test (VDRL) is a
Venereal Disease Research Laboratory test
6211483
Chow test The Chow test, proposed by econometrician Gregory Chow in 1960, is a test of whether the true coefficients in two linear regressions on different data sets are equal. In econometrics, it is most commonly used in time series analysis to test for the presence of a structural break at a period which can be assumed to be known "a priori" (for instance, a major historical event such as a war). In program evaluation, the Chow test is often used to determine whether the independent variables have different impacts on different subgroups of the population. Suppose that we model
Chow test
5817832
Unit root test In statistics, a unit root test tests whether a time series variable is non-stationary and possesses a unit root. The null hypothesis is generally defined as the presence of a unit root and the alternative hypothesis is either stationarity, trend stationarity or explosive root depending on the test used. In general, the approach to unit root testing implicitly assumes that the time series to be tested formula_1 can be written as, where, The task of the test is to determine whether the stochastic component contains a unit root or is stationary. A commonly used test that is
Unit root test
13326185
Seidel test The Seidel Test is used to assess the presence of anterior chamber leakage in the cornea. It is used as a screening test for many corneal disorders including corneal post-trauma, corneal perforation and corneal degeneration. The Seidel Test is named after the German Ophthalmologist Erich Seidel (1882–1948). Do not apply pressure on the eye during the test due to the risk of tissue extrusion. A fluorescein strip containing 10% fluorescein is applied topically to the affected area and is examined with a cobalt blue filter. At this point, the fluorescein appears green in color. Any changes in color
Seidel test
6116054
Kastle–Meyer test The Kastle–Meyer test is a presumptive blood test, first described in 1903, in which the chemical indicator phenolphthalein is used to detect the possible presence of hemoglobin. It relies on the peroxidase-like activity of hemoglobin in blood to catalyze the oxidation of phenolphthalin (the colorless reduced form of phenolphthalein) into phenolphthalein, which is visible as a bright pink color. The Kastle–Meyer test is a form of catalytic blood test, one of the two main classes of forensic tests commonly employed by crime labs in the chemical identification of blood. The other class of tests used for this purpose
Kastle–Meyer test
6605637
> C > A, then the Friedman test may be used. Bian, McAleer and Wong proposed in 2011 a non-parametric test for paired data when there are many ties. They showed that their trinomial test is superior to the sign test in presence of ties. Sign test The sign test is a statistical method to test for consistent differences between pairs of observations, such as the weight of subjects before and after treatment. Given pairs of observations (such as weight pre- and post-treatment) for each subject, the sign test determines if one member of the pair (such as pre-treatment) tends
Sign test
6667658
the Pearson chi-squared test gives a standardized test statistic of 2. Thus, we obtain a stronger significance level if the weights corresponding to additive (codominant) inheritance are used. Note that for the significance level to give a p-value with the usual probabilistic interpretation, the weights must be specified before examining the data, and only one set of weights may be used. Cochran–Armitage test for trend The Cochran–Armitage test for trend, named for William Cochran and Peter Armitage, is used in categorical data analysis when the aim is to assess for the presence of an association between a variable with two
Cochran–Armitage test for trend
19963773
positive test while nothing happening is a negative result. Cetrimide agar slants is a selective agar used to isolate "Pseudomonas aeruginosa""." The CLO test is used to diagnose "H. Pylori" in patient biopsies. A sample of the biopsy is places in a medium containing urea, which "H. Pylori" can use in some of its biochemical pathways. Consumption of urea indicates a positive test result. The coagulase test determines whether an organism can produce the enzyme coagulase, which causes the fibrin to clot. Inoculating a plasma test tube with the microbe indicates whether coagulase is produced. A clot indicates the presence
Diagnostic microbiology
15285313
Pre- and post-test probability Pre-test probability and post-test probability (alternatively spelled pretest and posttest probability) are the probabilities of the presence of a condition (such as a disease) before and after a diagnostic test, respectively. "Post-test probability", in turn, can be "positive" or "negative", depending on whether the test falls out as a positive test or a negative test, respectively. In some cases, it is used for the probability of developing the condition of interest in the future. Test, in this sense, can refer to any medical test (but usually in the sense of diagnostic tests), and in a broad
Pre- and post-test probability
13632943
exhaust system. The HGV test is a little more complex, as it also verifies tachograph operation and the presence of a road speed limiter. The DOE test is required every year, and without a pass certificate the vehicle cannot be taxed or used on the road. Doe test The term DOE test refers to an annual commercial vehicle test (CVT) required for goods vehicles in the Republic of Ireland. The DOE term refers to the Department of the Environment. The test was introduced in 1980. In 2005 Department of Transport took over jurisdiction over vehicle testing, and the test was
Doe test
3934804
Barfoed's test Barfoed's test is a chemical test used for detecting the presence of monosaccharides. It is based on the reduction of copper(II) acetate to copper(I) oxide (CuO), which forms a brick-red precipitate. (Disaccharides may also react, but the reaction is much slower.) The aldehyde group of the monosaccharide which normally forms a cyclic hemiacetal is oxidized to the carboxylate. A number of other substances, including sodium chloride, may interfere. It was invented by Danish chemist Christen Thomsen Barfoed and is primarily used in botany. The test is similar to the reaction of Fehling's solution to aldehydes. Barfoed's reagent consists
Barfoed's test
19963778
[[Decarboxylation|decarboxylate]] [[lysine]] and/or produce [[hydrogen sulfide]]. The [[lysostaphin test]] is used to differentiate between "Staphylococcus" and "Micrococcus" bacteria. [[Lysostaphin]] can [[Lysis|lyse]] "Staphylococcus," but "Micrococcus" bacteria are resistant to the chemical. [[File:Color_transition_of_Methyl_red_solution_under_different_acid-base_conditions.jpg|thumb|319x319px|Color transition of Methyl red solution under different acid-base conditions]] The [[methyl red test]] is used to analyze whether a bacterium produces acids through sugar fermentation. [[Microdase]] is a modified oxidase test used to differentiate "[[Micrococcus]]" from "[[Staphylococcus]]" by testing for the presence of [[cytochrome c]]. A positive result produces a dark color around the inoculant while negative result produces no color change. The [[nitrite test]] is commonly used to
Diagnostic microbiology
7737353
or dilute urine. In addition, a nitrite test does not detect organisms unable to reduce nitrate to nitrite, such as enterococci, staphylococci ("Staphylococcus saprophyticus"), Acinetobacter, or adenovirus. Nitrite test A nitrite test is a chemical test used to determine the presence of nitrite ion in solution. A common nitrite test can be performed by adding 4 M sulfuric acid to the sample until acidic, and then adding 0.1 M iron(II) sulfate to the solution. A positive test for nitrite is indicated by a dark brown solution, arising from the iron-nitric oxide complex ion. A nitrite test is a standard component
Nitrite test
17423235
FDA clearance on May 22, 2013. The BreathID Hp Breath Test System is used to perform a diagnostic test for the presence of "Helicobacter pylori", a bacterium that can cause peptic ulcers and is associated with gastric cancer. H.pylori is a very common bacterium, reported to be present in up to two-thirds of the world population. Blood or stool tests are also used to diagnose H. pylori. It takes days to get results from either test. The BreathID Hp test takes 10–15 minutes. Physicians receive results at the end of the test. Exalenz Bioscience Exalenz Bioscience Ltd. is a biotechnology
Exalenz Bioscience
10270563
antigens or antibodies can be attached to enzymes which can react to create a colorimetric result indicating the presence of the antibody or antigen of interest. Enzyme linked immunosorbent assays are used most commonly as diagnostic tests to detect HIV antibodies in blood samples to test for HIV, human chorionic gonadotropin molecules in urine to indicate pregnancy, and Mycobacterium tuberculosis antibodies in blood to test patients for tuberculosis. Furthermore, ELISA is also widely used as a toxicology screen to test people's serum for the presence of illegal drugs. Although there are three different types of solid state enzyme-linked immunosorbent assays,
Biomolecular engineering
6211485
total number of parameters (in this case, 3). Then the Chow test statistic is The test statistic follows the F distribution with formula_13 and formula_16 degrees of freedom. Remarks Chow test The Chow test, proposed by econometrician Gregory Chow in 1960, is a test of whether the true coefficients in two linear regressions on different data sets are equal. In econometrics, it is most commonly used in time series analysis to test for the presence of a structural break at a period which can be assumed to be known "a priori" (for instance, a major historical event such as a
Chow test
12277325
and acetamide don't give this test. The halogen used may be chlorine, bromine, iodine or sodium hypochlorite. Fluoroform (CHF) cannot be prepared by this method as it would require the presence of the highly unstable hypofluorite ion. However ketones with the structure RCOCF do cleave upon treatment with base to produce fluoroform; this is equivalent to the second and third steps in the process shown above. This reaction forms the basis of the iodoform test which was commonly used in history as a chemical test to determine the presence of a methyl ketone, or a secondary alcohol oxidizable to a
Haloform reaction
17890458
the result of a rotator cuff tear, while pain in the superior glenohumeral region is a weak predictor of a SLAP tear. Here are a list of anatomical terms with their associated links that are used in this article. Yergason's test Yergason's test is a special test used for orthopedic examination of the shoulder and upper arm region, specifically the biceps tendon. It identifies the presence of a pathology involving the biceps tendon or glenoid labrum. The specific positive findings to the test include: pain in the bicipital groove indicating biceps tendinitis, subluxation of the long head of the biceps
Yergason's test
13358615
1992, and of norfloxacin in 1993, in each case using a solution of iron(III) in suplphuric acid. It has also been used for the determination of the presence of bromazepan in 1992, using an iron(II) solution in a hydrochloric acid rather than an iron(III) solution. Trinder spot test The Trinder spot test is a diagnostic test used in medicine to determine exposure to salicylates, particularly to salicylic acid. The test employs the Trinder reagent (a.k.a. Trinder solution) which is mixed with a patient's urine. The colour change, resulting from the Trinder reaction, is immediate, enabling rapid bedside assessment. The Trinder
Trinder spot test
16162112
US ctizens and resident aliens living abroad are the same. However, foreign earned income may qualify for some amount of exclusion. One is to subtract the amounts that are estimated from the foreign earned income exclusion. Tax obligations may be reduced by subtracting the foreign housing exclusion but only from non-excluded income by using tax rates that would apply if the income were included. Physical presence test In international taxation, a physical presence test is a rule used to determine tax residence of a natural or legal person. It may rely on having a place of business in the jurisdiction
Physical presence test
4376459
larvae or eggs. Some bacterial diseases can be detected with a stool culture. Toxins from bacteria such as "Clostridium difficile" ("C. diff.") can also be identified. Viruses such as rotavirus can also be found in stools. A fecal pH test may be used to determine lactose intolerance or the presence of an infection. Steatorrhea can be diagnosed using a Fecal fat test that checks for the malabsorption of fat. Faecal elastase levels are becoming the mainstay of pancreatitis diagnosis. Stool test A stool test involves the collection and analysis of fecal matter to diagnose the presence or absence of a
Stool test
12893315
CPK-MB test The CPK-MB test is a cardiac marker used to assist diagnoses of an acute myocardial infarction. It measures the blood level of CK-MB (creatine kinase-muscle/brain), the bound combination of two variants (isoenzymes CKM and CKB) of the enzyme phosphocreatine kinase. In some locations, the test has been superseded by the troponin test. However, recently, there have been improvements to the test that involve measuring the ratio of the CK-MB1 and CK-MB2 isoforms. The newer test detects different isoforms of the B subunit specific to the myocardium whereas the older test detected the presence of cardiac-related isoenzyme dimers. Many
CPK-MB test
11028624
Duquenois–Levine reagent The Duquenois reagent is used in the Rapid Modified Duquenois–Levine test (also known as the simple Rapid Duquenois Test), is an established screening test for the presence of marijuana. The test was initially developed in the 1930s by the French Medical Biochemist, Pierre Duquénois (1904–1986), and was adopted in the 1950s by the United Nations as the preferred test for cannabis, and originally claimed to be specific to cannabis. After several modifications, it became known as the Duquenois–Levine test. However, in the 1960s and 70s various studies showed that the test was not specific to cannabis. In 1973
Duquenois–Levine reagent
11006437
published a procedure for simultaneous determination of pentoses and hexoses from measurements at two wavelengths. Various versions of this test are widely used for a quick chemical determination of RNA; in this context it is usually called the orcinol test. Bial's test Bial's test is a chemical test for the presence of pentoses. It is named after Manfred Bial, a German physician. The components include orcinol, hydrochloric acid, and ferric chloride. A pentose, if present, will be dehydrated to form furfural which then reacts with the orcinol to generate a colored substance. The solution will turn bluish and a precipitate
Bial's test
5825687
methyl red may be prepared by diazotization of anthranilic acid, followed by reaction with dimethylaniline: Methyl red displays pH dependent photochromism, with protonation causing it to adopt a hydrazone/quinone structure. Methyl Red has a special use in Histopathology for showing acidic nature of tissue and presence of organisms with acidic natured cell walls. In microbiology, methyl red is used in the methyl red test (MR test), used to identify bacteria producing stable acids by mechanisms of mixed acid fermentation of glucose ("cf." Voges–Proskauer test). The MR test, the "M" portion of the four IMViC tests, is used to identify enteric
Methyl red
7290956
indicative of the presence of renovascular disease. CCT in adults is known to have high sensitivity, but a low specificity. Subtraction angiography is considered a more suitable test for renal artery stenosis in adults. Captopril challenge test The captopril challenge test (CCT) is a non-invasive medical test that measures the change in renin plasma-levels in response to administration of captopril, an angiotensin converting enzyme inhibitor. It is used to assist in the diagnosis of renal artery stenosis. It is not generally considered a useful test for children, and more suitable options are available for adult cases. Plasma concentration of renin
Captopril challenge test
5188557
produced from regular triplet oxygen. Because free radicals are highly reactive, the damage is limited to the body part illuminated. 3T3 Neutral Red Phototoxicity Test – An in vitro toxicological assessment test used to determine the cytotoxic and photo(cyto)toxicity effect of a test article to murine fibroblasts in the presence or absence of UVA light. "The 3T3 Neutral Red Uptake Phototoxicity Assay (3T3 NRU PT) can be utilized to identify the phototoxic effect of a test substance induced by the combination of test substance and light and is based on the comparison of the cytotoxic effect of a test substance
Phototoxicity
11072365
that the dispersion of the two groups is the same. The Siegel–Tukey test has relatively low power. For example, in the presence of values distributed as a Gaussian, power is equal to 61%. Siegel–Tukey test In statistics, the Siegel–Tukey test, named after Sidney Siegel and John Tukey, is a non-parametric test which may be applied to data measured at least on an ordinal scale. It tests for differences in scale between two groups. The test is used to determine if one of two groups of data tends to have more widely dispersed values than the other. In other words, the
Siegel–Tukey test
7446987
that will still yield a positive CF test. This dilution factor corresponds to the titer. Complement fixation test The complement fixation test is an immunological medical test that can be used to detect the presence of either specific antibody or specific antigen in a patient's serum, based on whether complement fixation occurs. It was widely used to diagnose infections, particularly with microbes that are not easily detected by culture methods, and in rheumatic diseases. However, in clinical diagnostics labs it has been largely superseded by other serological methods such as ELISA and by DNA-based methods of pathogen detection, particularly PCR.
Complement fixation test
14942688
Xanthoproteic reaction The xanthoproteic reaction is a method that can be used to determine the amount of protein soluble in a solution, using concentrated nitric acid. The test gives a positive result in amino acids carrying aromatic groups, especially in the presence of tyrosine. If the test is positive the proof is neutralized with an alkali, turning dark yellow. The yellow colour is due to xanthoproteic acid which is formed due to nitration of certain amino acids, most common examples being tyrosine and tryptophan. This chemical reaction is a qualitative test, determining the presence or absence of proteins. Add 1
Xanthoproteic reaction
19047003
Four prism dioptre reflex test The Four Prism Dioptre Reflex Test (also known as the 4 PRT, or 4 Prism Dioptre Base-out Test), is an objective, non-dissociative test used to prove the alignment of both eyes (i.e. the presence of binocular single vision) by assessing motor fusion. Through the use of a 4 dioptre base out prism, diplopia is induced which is the driving force for the eyes to change fixation and therefore re-gain bifoveal fixation meaning, they overcome that amount of power. This test is performed on patients suspected to have small angle deviations of less than 10 prism
Four prism dioptre reflex test
601283
– which is by far the most common type of hearing loss. As such, speech-in-noise tests can provide valuable information about a person's hearing ability, and can be used to detect the presence of a sensorineural hearing loss. A recently developed digit-triple speech-in-noise test may be a more efficient screening test. Otoacoustic emissions test is an objective hearing test that may be administered to toddlers and children too young to cooperate in a conventional hearing test. The test is also useful in older children and adults and is an important measure in diagnosing auditory neuropathy described above. Auditory brainstem response
Hearing loss
14810280
that is analyzed and the method used to obtain results. Nevertheless, dip slides may be very useful as they are very convenient, simple to use and cost effective. Dip slide A dip slide (or dipslide) is a test for the presence of microorganisms in liquids. The use of dip slides is the method most frequently used to measure and observe microbial activity in liquid-based systems. It is often used in testing cooling systems. Dip slides are often used to determine the presence of slime forming bacteria in cooling & industrial water systems. The dip slide test consists of a sterile
Dip slide
19249890
Green Card Test The Green Card Test (GCT) is a criterion used by the Internal Revenue Service (IRS) in the United States to determine whether an individual qualifies as a "resident for tax purposes". The GCT asks whether, during the calendar year, an individual spent at least one day in the US as a lawful permanent resident (i.e. possessed a green card). In particular, it is not required to possess a green card when the individual files a return. The GCT is used alongside the Substantial Presence Test; specifically, an alien is considered a "resident for tax purposes" if they
Green Card Test
11650282
butanediol fermentation is used. The VP test uses alpha-naphthol and potassium hydroxide to test for the presence of acetylmethylcarbinol (acetoin), an intermediate of the 2,3-butanediol fermentation pathway. After adding both reagents, the tube is shaken vigorously then allowed to sit for 5-10 minutes. A pinkish-red color indicates a positive test, meaning the 2,3-butanediol fermentation pathway is used. This test uses Simmon's citrate agar to determine the ability of a microorganism to use citrate as its sole carbon source. The agar contains citrate and ammonium ions (nitrogen source) and bromothymol blue as an indicator. The citrate agar is green before inoculation,
IMViC
4549304
at inducing thrombosis, it has been incorporated into an "in vitro" diagnostic test for blood clotting that is widely used in hospital laboratories. This test is often referred to as dilute Russell's viper venom time (dRVVT). The coagulant in the venom directly activates factor X, which turns prothrombin into thrombin in the presence of factor V and phospholipid. The venom is diluted to give a clotting time of 23 to 27 seconds and the phospholipid is reduced to make the test extremely sensitive to phospholipid. The dRVVT test is more sensitive than the aPTT test for the detection of lupus
Russell's viper
11650279
IMViC The IMViC tests are a group of individual tests used in microbiology lab testing to identify an organism in the coliform group. A coliform is a gram negative, aerobic or facultative anaerobic rod which produces gas from lactose within 48 hours. The presence of some coliforms indicate fecal contamination. The term "IMViC" is an acronymm for each of these tests. "I" is for indole test; "M" is for methyl red test; "V" is for Voges-Proskauer test, and "C" is for citrate test. The lower case "i" is merely for "in" as the Citrate test requires coliform samples to be
IMViC
11609316
Rapid strep test The rapid strep test (RST) is a rapid antigen detection test (RADT) that is widely used in clinics to assist in the diagnosis of bacterial pharyngitis caused by group A streptococci (GAS), sometimes termed strep throat. There are currently several types of rapid strep test in use, each employing a distinct technology. However, they all work by detecting the presence of GAS in the throat of a person by responding to GAS-specific antigens on a throat swab. A rapid strep test may assist a clinician in deciding whether to prescribe an antibiotic to a person with pharyngitis,
Rapid strep test
5575394
in forensics for many years to test for the traces of nitroglycerine. Caustic soda is used to break down the molecule of nitroglycerine to produce nitrite ions. The concentration of this caustic soda is crucial to the test. The test involves the taking of a sample with ether and its division into two bowls. Sodium hydroxide is added to the first bowl followed by the Griess reagent; if the solution turns pink within ten seconds, this indicates the presence of nitrites. The test itself is positive if, after adding only Griess reagent to the second bowl, the solution there remains
Griess test
375913
present will color red. Benedict's test and Fehling's test is also done to indicate the presence of starch. Starch indicator solution consisting of water, starch and iodide is often used in redox titrations: in the presence of an oxidizing agent the solution turns blue, in the presence of reducing agent the blue color disappears because triiodide (I) ions break up into three iodide ions, disassembling the starch-iodine complex. Starch solution was used as indicator for visualizing the periodic formation and consumption of triiodide intermediate in the Briggs-Rauscher oscillating reaction. The starch, however, changes the kinetics of the reaction steps involving
Starch
13473724
Colorimetric assays use reagents that undergo a measurable color change in the presence of the analyte. They are widely used in biochemistry to test for the presence of enzymes, specific compounds, antibodies, hormones and many more analytes. For example, Colorimetry (chemical method) In physical and analytical chemistry, colorimetry or colourimetry is a technique "used to determine the concentration of colored compounds in solution." A colorimeter is a device used to test the concentration of a solution by measuring its absorbance of a specific wavelength of light (not to be confused with the tristimulus colorimeter used to measure colors in general).
Colorimetry (chemical method)
9923942
while other studies show a difference. Despite these reports, the Benton Test has several advantages over other tests of visual memory. These include: a more explicit scoring system than other tests, parallel-forms reliability due to the presence of multiple form sets, and short administration time. Because of this, the BVRT is still widely used today for a large number of clinical conditions. Benton Visual Retention Test The Benton Visual Retention Test (or simply Benton test or BVRT) is an individually administered test for people aged from eight years to adulthood that measures visual perception and visual memory. It can also
Benton Visual Retention Test
19963774
of coagulase, while no clot indicates the lack of coagulase. DNase agar is used to test whether a microbe can produce the exoenzyme deoxyribonuclease (DNase), which hydrolyzes DNA. Methyl green is used as an indicator in the growth medium because it is a cation that is provides an opaqueness to a medium with the presence of negatively charged DNA strands. When DNA is cleaved, the media becomes clear, showing the presence of DNase activity. The gelatin test is used to analyze whether a microbe can hydrolyze gelatin with the enzyme gelatinase. The gelatin makes the agar solid, so if an
Diagnostic microbiology
14810276
Dip slide A dip slide (or dipslide) is a test for the presence of microorganisms in liquids. The use of dip slides is the method most frequently used to measure and observe microbial activity in liquid-based systems. It is often used in testing cooling systems. Dip slides are often used to determine the presence of slime forming bacteria in cooling & industrial water systems. The dip slide test consists of a sterile culture medium on a plastic carrier that is dipped into the liquid to be sampled. The culture is then incubated, allowing for microbial growth. Most Dip slides consist
Dip slide
5575392
Griess test The Griess test is an analytical chemistry test which detects the presence of nitrite ion in solution. One of its most important uses is the determination of nitrite in drinking water. The test has also been widely used for the detection of trace explosives containing nitro groups. It is usually necessary to release the nitrite ion from the organic explosive before analysis. This is normally done by alkaline hydrolysis. The "Griess diazotization reaction" on which the Griess reagent relies was first described in 1858 by Peter Griess. Nitrite is detected and analyzed by formation of a red pink
Griess test
15725747
Bechdel test The Bechdel test ( ), also known as the Bechdel–Wallace test, is a measure of the representation of women in fiction. It asks whether a work features at least two women who talk to each other about something other than a man. The requirement that the two women must be named is sometimes added. About half of all films meet these criteria, according to user-edited databases and the media industry press. The test is used as an indicator for the active presence of women in films and other fiction, and to call attention to gender inequality in fiction.
Bechdel test
19397741
clues and a < 0.03% at 0–2 cues or clues. The police may also then check for Vertical Gaze Nystagmus, which is used to test for high blood alcohol levels and/or the presence of certain drugs. While the purpose is obtaining probable cause support for an arrest and possibly screening, in some jurisdictions, the HGN test may be used as corroborating evidence at the trial stage. US jurisdictions differ on whether trial use of the HGN test requires that an expert establish a reliable foundation, as required under the "Daubert" standard The second test that is usually administered is the
Field sobriety testing
2572814
benzene: The ferric chloride test is a traditional colorimetric test for phenols, which uses a 1% iron(III) chloride solution that has been neutralised with sodium hydroxide until a slight precipitate of FeO(OH) is formed. The mixture is filtered before use. The organic substance is dissolved in water, methanol or ethanol, then the neutralised iron(III) chloride solution is added—a transient or permanent coloration (usually purple, green or blue) indicates the presence of a phenol or enol. This reaction is exploited in the Trinder spot test, which is used to indicate the presence of salicylates, particularly salicylic acid, which contains a phenolic
Iron(III) chloride
547624
and amoxicillin) before repeating the smear. Alternatively, the test will be repeated at an earlier time than it would otherwise. If there are symptoms of vaginal discharge, bad odor or irritation, the presence of coccoid bacteria also may indicate treatment with antibiotics as per above. Pap test The Papanicolaou test (abbreviated as Pap test, also known as Pap smear, cervical smear, cervical screening or smear test) is a method of cervical screening used to detect potentially pre-cancerous and cancerous processes in the cervix (opening of the uterus or womb). Abnormal findings are often followed up by more sensitive diagnostic procedures,
Pap test
4919771
Flame test A flame test is an analytic procedure used in chemistry to detect the presence of certain elements, primarily metal ions, based on each element's characteristic emission spectrum. The color of flames in general also depends on temperature; see flame color. The test involves introducing a sample of the element or compound to a hot, non-luminous flame, and observing the color of the flame that results. The idea of the test is that sample atoms evaporate and since they are hot, they emit light when being in flame. Bulk sample emits light too, but its light is not good
Flame test
5575396
The reagent should not be stored more than three months. Griess test The Griess test is an analytical chemistry test which detects the presence of nitrite ion in solution. One of its most important uses is the determination of nitrite in drinking water. The test has also been widely used for the detection of trace explosives containing nitro groups. It is usually necessary to release the nitrite ion from the organic explosive before analysis. This is normally done by alkaline hydrolysis. The "Griess diazotization reaction" on which the Griess reagent relies was first described in 1858 by Peter Griess. Nitrite
Griess test
19963775
organism can produce gelatinase and consume gelatin as an energy and carbon source, the agar will become liquid during growth. The Gonochek II test, a commercial biochemical test, is used to differentiate between "Neisseria lactamica", "Neisseria meningitidis", "N. gonorrhoeae" and "Moraxella catarrhalis." The principle behind this test is to use enzymes native to the organism to create a colored product in the presence of foreign molecules. The chemical [[5-bromo-4-chloro-3-indolyl-beta-D-galactoside is used in the test because "N. lactamica" can hydrolyze it with the production of β-[[Galactosidases|galactosidase]], turning the solution into a blue color. Gamma-glutamyl-p-nitroanilide is added to the solution to indicate
Diagnostic microbiology
12041866
out via urine. Also, it can be used to detect salicylates in urine after aspirin overdose. Ferric chloride test The ferric chloride test is used to determine the presence of phenols in a given sample or compound (for instance natural phenols in a plant extract). Enols, hydroxamic acids, oximes, and sulfinic acids give positive results as well. The bromine test is useful to confirm the result, although modern spectroscopic techniques (e.g. NMR and IR spectroscopy) are far superior in determining the identity of the unknown. The quantity of total phenols may be spectroscopically determined by the Folin-Ciocalteau assay. The sample
Ferric chloride test
8727713
work in the United States, and therefore do not have any income tax obligations. However, they still need to file Form 8843, as discussed below. There are two tests to determine permanent residency: the Green Card Test and the Substantial Presence Test. Almost everybody in student status is likely to fail the Green Card Test since it applies only to people who have held a green card in the tax year. The relevant test for students is therefore the Substantial Presence Test. By the Substantial Presence Test, a person who is in the United States for at least 31 days
F visa
389731
Messaging and Presence Leveraging Extensions (SIMPLE) is the SIP-based suite of standards for instant messaging and presence information. MSRP (Message Session Relay Protocol) allows instant message sessions and file transfer. The SIP developer community meets regularly at conferences organized by SIP Forum to test interoperability of SIP implementations. The TTCN-3 test specification language, developed by a task force at ETSI (STF 196), is used for specifying conformance tests for SIP implementations. When developing SIP software or deploying a new SIP infrastructure, it is very important to test capability of servers and IP networks to handle certain call load: number of
Session Initiation Protocol
7446984
Complement fixation test The complement fixation test is an immunological medical test that can be used to detect the presence of either specific antibody or specific antigen in a patient's serum, based on whether complement fixation occurs. It was widely used to diagnose infections, particularly with microbes that are not easily detected by culture methods, and in rheumatic diseases. However, in clinical diagnostics labs it has been largely superseded by other serological methods such as ELISA and by DNA-based methods of pathogen detection, particularly PCR. The complement system is a system of serum proteins that react with antigen-antibody complexes. If
Complement fixation test
8060041
presence of the disease in a patient. A positive result in a test with high sensitivity is not useful for ruling in disease. Suppose a 'bogus' test kit is designed to show only one reading, positive. When used on diseased patients, all patients test positive, giving the test 100% sensitivity. However, sensitivity by definition does not take into account false positives. The bogus test also returns positive on all healthy patients, giving it a false positive rate of 100%, rendering it useless for detecting or "ruling in" the disease. Sensitivity is not the same as the precision or positive predictive
Sensitivity and specificity
433173
test is a measure of the amount of nitrogen in the blood that comes from urea. It is used as a marker of renal function, though it is inferior to other markers such as creatinine because blood urea levels are influenced by other factors such as diet and dehydration. Urea labeled with carbon-14 or carbon-13 is used in the urea breath test, which is used to detect the presence of the bacterium "Helicobacter pylori" ("H. pylori") in the stomach and duodenum of humans, associated with peptic ulcers. The test detects the characteristic enzyme urease, produced by "H. pylori", by a
Urea
6409867
of several ways. The test may be performed by a technician directly, with the assistance of a machine, or completely by an automated machine. Machine based tests aid diagnostics by allowing a detailed printout of the patient's visual field. Other names for this test may include perimetry, Tangent screen exam, Automated perimetry exam, Goldmann visual field exam, or the Humphrey field exam. Techniques used to perform this test: Perimetry or campimetry is one way to systematically test the visual field. It is the systematic measurement of differential light sensitivity in the visual field by the detection of the presence of
Visual field test
14052954
Voges–Proskauer test Voges–Proskauer or VP is a test used to detect acetoin in a bacterial broth culture. The test is performed by adding alpha-naphthol and potassium hydroxide to the Voges-Proskauer broth which has been inoculated with bacteria. A cherry red color indicates a positive result, while a yellow-brown color indicates a negative result. The test depends on the digestion of glucose to acetylmethylcarbinol. In the presence of oxygen and strong base, the acetylmethylcarbinol is oxidized to diacetyl, which then reacts with guanidine compounds commonly found in the peptone medium of the broth. Alpha-naphthol acts as a color enhancer, but the
Voges–Proskauer test
4364138
Widal test In 1896 and named after its inventor, Georges-Fernand Widal, is a presumptive serological test for enteric fever or undulant fever whereby bacteria causing typhoid and malaria fever(caused by protozoa) are mixed with a serum containing specific antibodies obtained from an infected individual. In cases of "Salmonella" infection, it is a demonstration of the presence of O-soma false-positive result. Test results need to be interpreted carefully to account for any history of enteric fever, typhoid vaccination, and the general level of antibodies in the populations in endemic areas of the world. Typhidot is the other test used to ascertain
Widal test
11609323
of a positive RST result from a person with a sore throat. US guidelines recommend following up a negative result with a microbial culture, whereas European guidelines suggest relying on the negative RST. Rapid strep test The rapid strep test (RST) is a rapid antigen detection test (RADT) that is widely used in clinics to assist in the diagnosis of bacterial pharyngitis caused by group A streptococci (GAS), sometimes termed strep throat. There are currently several types of rapid strep test in use, each employing a distinct technology. However, they all work by detecting the presence of GAS in the
Rapid strep test
4811465
with ferrous sulphate. Sodium fusion test The sodium fusion test, or Lassaigne's test, is used in elemental analysis for the qualitative determination of the presence of foreign elements, namely halogens, nitrogen, and sulphur, in an organic compound. It was developed by J. L. Lassaigne. The test involves heating the sample strongly with clean sodium metal, "fusing" it with the sample. A variety of techniques has been described. The "fused" sample is plunged into water, and the usual qualitative tests are performed on the resultant solution for the respective possible constituents. The halogens, nitrogen and sulphur are covalently bonded to the
Sodium fusion test
4811463
Sodium fusion test The sodium fusion test, or Lassaigne's test, is used in elemental analysis for the qualitative determination of the presence of foreign elements, namely halogens, nitrogen, and sulphur, in an organic compound. It was developed by J. L. Lassaigne. The test involves heating the sample strongly with clean sodium metal, "fusing" it with the sample. A variety of techniques has been described. The "fused" sample is plunged into water, and the usual qualitative tests are performed on the resultant solution for the respective possible constituents. The halogens, nitrogen and sulphur are covalently bonded to the organic compounds. In
Sodium fusion test
13671854
uptake suggests the presence of a nodule. I has a shorter half-life than I (a half day vs. 8.1 days), so use of I exposes the body to less radiation, at the expense of less time to evaluate delayed scan images. Furthermore, I emits gamma radiation, while I emits gamma and beta radiation. The test is inappropriate for patients who are pregnant or breastfeeding. Radioactive iodine uptake test The radioactive iodine uptake test, or RAIU test, is a type of scan used in the diagnosis of thyroid problems, particularly hyperthyroidism. It is entirely different from radioactive iodine therapy (RAI therapy),
Radioactive iodine uptake test