Monoclonal antibodies based sandwich erythro-immunoassay and dot enzyme immunoassay for human chorionic gonadotropin in urine

Abstract

Two simple solid-phase sandwich immunoassays for human chorionic gonadotropin (hCG) employing monoclonal antibodies have been described. One is a sandwich erythro-immunoassay employing V-shaped well microtitration plates coated with monoclonal anti-β-hCG antibody and monoclonal anti-α-hCG antibody labelled sheep erythrocytes. The second is a dot enzyme immunoassay employing dip-stick (plastic strips pasted with nitrocellulose pads) coated with monoclonal anti-β-hCG antibody. Anti-α-hCG monoclonal-alkaline phosphatase conjugate was used to reveal hCG bound to solid surface. The assays can be performed by one-step or two-step procedures. Erythro-immunoassay as well as dot enzyme immunoassay was able to detect in urine as low as 10 mIU hCG/ml. A good correlation was observed between the values obtained by these two methods as well as two-step sandwich enzyme immunoassay on 47 urine samples.