Radioimmunoassay of 11-Deoxycortisol. Specificity of Antisera raised against 11-Deoxycortisol-[C-4]-Bovine Serum Albumin Conjugates

Abstract

In order to obtain specific antisera for use in immunoassays of 11-deoxycortisol, new hapten-carrier conjugates were prepared from 4-hemisuccinoyloxy-11-deoxycortisol, 4-(carboxymethylthio)-11-deoxycortisol, 4-(2-carboxyethylthio)-11-deoxycortisol and 4-(2-hemisuccinoyloxyethylthio)-11-deoxycortisol by coupling with bovine serum albumin employing the N-succinimidyl ester method. The specificity of anti-11-deoxycortisol antisera elicited in rabbits by immunization with these antigens was tested by crossreaction studies with closely related steroids and by measuring the amount of 11-deoxycortisol in plasma specimens by means of radioimmunoassay. The results showed that the antisera obtained were reasonably specific and useful for the determination of plasma 11-deoxycortisol levels in metyrapone tests. The assay can be done on methylene chloride extracts of plasma.