Rapid Enzyme Immunoassay for Human Choriogonadotropin in Serum using Horseradish Peroxidase as a Label

Abstract

A rapid sandwich-type enzyme immunoassay of human choriogonadotropin in 20 μl of serum is described. Anti-human choriogonadotropin β subunitantibody (IgG fraction) was coated on an acrylonitrile-butadiene-styrene copolymer bead. The bead was incubated with choriogonadotropin in serum at 30°C for 2 (or 3) h, and again incubated at 30°C for 2 (or 3) h with antibody-labeled horseradish peroxidase prepared by Nakane and Kawaoi's method, to form a sandwich-type immunocomplex. The enzyme activity of the complex on the bead was measured by the use of a sensitive fluorogenic substrate, 3-(p-hydroxyphenyl) propionic acid. The method permits one-day assay of 0.0125-64 ng (2.75-14080 mIU) of the hormone.