It uses flow programming instead of the continuous flow regime (as used by CFA and FIA), that allows the flow rate and flow direction to be tailored to the need of individual steps of analytical protocol. Reactants are mixed by flow reversals and a measurement is carried out while the reaction mixture is arrested within the detector by stopping the flow. Microminiaturized chromatography is carried out on microcolumns that are automatically renewed by microfluidic manipulations. The discrete pumping and metering of microliter sample and reagent volumes used in SI only generates waste per each sample injection. The enormous volume of FI and SI literature documents the versatility of FI and SI and their usefulness for routine assays (in soil, water, environmental, biochemical and biotechnological assays) has demonstrated their potential to be used as a versatile research tool. Dialyzer module In medical testing applications and industrial samples with high concentrations or interfering material, there is often a dialyzer module in the instrument in which the analyte permeates through a dialysis membrane into a separate flow path going on to further analysis. The purpose of a dialyzer is to separate the analyte from interfering substances such as protein, whose large molecules do not go through the dialysis membrane but go to a separate waste stream. The reagents, sample and reagent volumes, flow rates, and other aspects of the instrument analysis depend on which analyte is being measured. The autoanalyzer is also a very small machine Recording of results Previously a chart recorder and more recently a data logger or personal computer records the detector output as a function of time so that each sample output appears as a peak whose height depends on the analyte level in the sample. Commercialization Technicon sold its business to Revlon in 1980 who later sold the company to separate clinical (Bayer) and industrial (Bran+Luebbe - now SEAL Analytical) buyers in 1987. At the time, industrial applications accounted for about 20% of CFA machines sold. In 1974 Ruzicka and Hansen carried out in Denmark and in Brasil initial experiments on a competitive technique, that they termed flow injection analysis (FIA). Since then the technique found worldwide use in research and routine applications, and was further modified through miniaturization and by replacing continuous flow with computer controlled programmable flow. During the 1960s industrial laboratories were hesitant to use the autoanalyzer. Acceptance by regulatory agencies eventually came about by