Development of an enzyme-linked receptor assay (ERA) for hCG

An enzyme-linked receptor assay (ERA) for hCG was developed using horseradish peroxidase. The 1,500 g pellets, interstitial cell fraction, and solubilized homogenate from the rat testis linked to tanned sheep red blood cells (SRBC) were used as the binding fractions for hCG. In these ERA systems, the limit of detection for hCG was 30 IU/l (3-12 mIU/tube), which was almost equal to that of radio receptor assay (RRA). The ERA using SRBC linked solubilized receptor fraction showed the most satisfactory result in accuracy, reproducibility and easiness.