title: Enzyme-linked sandwich immunoassay for insulin using laser fluorimetric detection.
abstract: Human serum samples are assayed for insulin by an enzyme-linked sandwich immunoassay. Horseradish peroxidase is used as an enzyme label for antibody, and enzyme activity is measured by means of the fluorogenic substrate, p-hydroxyphenylacetic acid. The product is detected by excitation of fluorescence with the 325-nm line of a continuous-wave helium/cadmium ion laser on line with reverse-phase high-pressure liquid chromatography. The incubation period is 90 min and the limit of detection of insulin is 30 pM, corresponding to 5 microunits/ml. This method correlates highly with radioimmunoassay, with coefficient of correlation r = 0.95.
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007328:Insulin / Q000097:blood*; D007834:Lasers; D013050:Spectrometry, Fluorescence / Q000295:instrumentation
chemical_list: D007328:Insulin