Enzyme immunoassay (EIA) methods of TSH, cortisol and testosterone were developed and evaluated for clinical use. TSH-alkaline phosphatase (ALP), cortisol-21-hemisuccinate-ALP and testosterone-3-oxime-glucoamylase conjugates were used and B-F was separated by double antibody technique. Values for serum TSH, cortisol and testosterone determined by EIA correlated with those determined by radioimmunoassay. The good recovery of these hormones added to serum and the low coefficient of variation indicate that these methods are applicable for routine tests.
