title: A microassay system for measuring esterase activity and protein concentration in small samples and in high-pressure liquid chromatography eluate fractions.
abstract: A microtiter plate spectrophotometric system has been used together with the Bradford, Ellman, and van Asperen assays to measure protein concentration (to 0.5 microgram) and the activities of acetylcholinesterase (to 10(-3) units) and carboxylesterase (to 30 micrograms beta-naphthol reaction product) in small samples such as high-performance liquid chromatographic eluate fractions. For 100-microliter samples, at least 300 Ellman acetylcholinesterase or Bradford protein assays can be conducted and read in less than 30 min, and a like number of van Asperen nonspecific esterase assays (including 1-h incubation) run in less than 90 min. The eluate from a single 20-min high-performance liquid chromatographic run of a biological sample can be collected as up to 300 fractions directly into microtiter plate wells, and the three assays run on all fractions in less than 90 min.
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis* / Q000378:metabolism; D000818:Animals; D002265:Carboxylic Ester Hydrolases / Q000032:analysis* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D008099:Liver / Q000201:enzymology; D009132:Muscles / Q000201:enzymology; D011817:Rabbits; D013053:Spectrophotometry; D013552:Swine
chemical_list: D002265:Carboxylic Ester Hydrolases; D000110:Acetylcholinesterase