Some observations on the determination of testosterone in human plasma by radioimmunoassay using antisera raised against testosterone-3-BSA and testosterone-11 -BSA

The use of two antisera for testosterone (T) were compared in the radioimmunoassay of the steroid. The sera, anti-T-3-BSA and anti-T-11α-BSA, were used to examine the effect of alumina thin layer chromatography on the titres of male and female plasmas. It was demonstrated that the chromatographic step did not make a great deal of difference to the result for male plasma but for female plasma relatively large falls in the titre were observed when the step was included. 5α-Dihydrotestosterone and 11-oxy-C₁₉-steroids respectively were considered to be at least partially responsible for the discrepancies. Assay criteria were examined in some detail and a comparison of the radioimmunoassay method with gas liquid chromatographic analysis was made. Good correlation was achieved between the two procedures.