Abstract
A direct method for the radioimmunoassay of male serum testosterone is described which does not require extraction by organic solvents. Interference from sex hormone binding proteins is removed by adding a gross excess of estradiol to each sample. Separation of bound and free 3H-testosterone is by means of serum dextran coated charcoal. Data indicating the accuracy and reproducibility of this method are presented and the possibility of one-step radioimmunoassay of serum testosterone is discussed.
