Radioimmunoassay method of androgen determination (testosterone and dihydrotestosterone) in human male blood serum without extraction and chromatography

A radioimmunoassay method for androgen determination (testosterone and dihydrotestosterone) in blood serum, without extraction and chromatography, has been described. Antibodies obtained by immunization of animals with testosterone-3-carboxymethyl oxime coupled to bovine serum albumin were used. The antibody obtained was homogenous and specific, with the association constant of 5.71 X 109 l/mol. The interference of sex-hormone binding proteins present in human blood plasma was removed by heating. The results of determinations of blood plasma androgen levels obtained by using the direct method were in agreement with those obtained by applying radioimmunoassay with extraction and chromatography. The intra- and inter-assay coefficients of variation were low. (author)