The Preparation of Steroid N-Hydroxysuccinimide Esters and Their Reactivities with Bovine Serum Albumin

Abstract

The N-hydroxysuccinimide esters of testosterone and cortisol were prepared from the corresponding carboxylic acid derivatives by a carbodiimide method. These activated esters were covalently linked to bovine serum albumin in organic solvent/phosphate buffer (pH 7.4) employing various molar ratios of the steroid to protein. The results indicated that the activated ester method would be useful for enzyme labeling in enzyme immunoassay of steroids in respects of simplicity and reproducibility.