Enzyme immunoassay of testosterone using the testosterone-glucoamylase complex

A highly sensitive, reproducible method was established for enzyme-coupled immunoassay of testosterone, involving coupling of testosterone to glucoamylase [EC 3.2.1.3] with a water-soluble coupling reagen carbodimide. No enzyme activity was lost during this coupling procedure. The sensitivity of the method was comparable to that of competitive protein binding assay.