title: A simple robust assay for testosterone in male plasma using an 125I-radioligand and a solid-phase separation technique.
abstract: A radioimmunoassay for testosterone in male plasma utilising a gamma-emitting radioligand and a solid-phase antiserum is described. The radioligand is testosterone-3-(O-carboxymethyl)-oxime coupled to 125I-iodohistamine, and the solid-phase antiserum is prepared by coupling antitestosterone-3-bovine serum albumin to cyanogen bromide activated cellulose. The new procedure retains much of the specificity associated with a published, specific radioimmunoassay using an antiserum raised against testosterone-11 alpha-BSA and a tritium radioligand and incorporating a dextra-coated charcoal separation procedure; values obtained by the two procedures are in excellent agreement (r = 0.98, n = 20). The combination of an 125I-radioligand and a solid-phase separation technique greatly increases sample throughput and has the further advantage of reduced running costs and a greater potential for automation. The method gives satisfactory levels of sensitivity, precision, and accuracy.
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D006801:Humans; D007106:Immune Sera; D007457:Iodine Radioisotopes; D008297:Male; D011817:Rabbits; D011863:Radioimmunoassay / Q000379:methods*; D011869:Radioligand Assay / Q000379:methods*; D013739:Testosterone / Q000097:blood*
chemical_list: D006063:Chorionic Gonadotropin; D007106:Immune Sera; D007457:Iodine Radioisotopes; D013739:Testosterone