Specific enzyme immunoassay for human chorionic gonadotropin using antibody to the synthetic peptide corresponding to the carboxyl-terminal region of the beta-subunit of hCG.

A sandwich-type enzyme immunoassay for human chorionic gonadotropin (hCG) was developed with anti hCG-beta antibody-enzyme complex and the immobilized solid-phase antibody which was prepared from the antiserum to the synthetic peptide corresponding to the carboxyl-terminal region of the beta-subunit of hCG (hCG-beta). This assay system showed a high sensitivity equal to the radioimmunoassay and did not cross-react with human luteinizing hormone (hLH), human follicle stimulating hormone (hFSH) or alpha-subunit of hCG (hCG-alpha). The coefficients of variation in within-run and between-run were less than 10% and there was a good correlation between the enzyme immunoassay and the radioimmunoassay of serum sample with a regression equation of y = 1.038 x -0.647 and a correlation coefficient of r = 0.953.