A method for the determination of sex hormone binding globulin in human serum

A simple and rapid method for serum sex hormone binding globulin (SHBG) was developed. Sera from pregnant women were pooled and the SHBG concentration was measured by Rosner's method. This pool was diluted with charcoal-treated and heated serum to give standards ranging in concentrations from 26.8-0.8 micrograms/L. Two sets of tubes containing dihydrotestosterone (DHT), assay and control tubes, were prepared. Diluted standards and unknowns were added to assay and control tubes along with tritiated DHT. Following incubation, cold saturated ammonium sulfate was added to each tube, mixed, centrifuged and the supernatant counted. Mean SHBG concentration (microgram/L +/- SEM) in normal men was 3.6 +/- 0.4, normal women 11.4 +/- 2.2, pregnant women 58 +/- 2.6, obese women 3.3 +/- 1.0, hirsute women 2.9 +/- 0.2, hypothyroid women 7.3 +/- 1.0, and hyperthyroid women 26.0 +/- 1.6. These results correlate well with previous reports. This method is fast, convenient, and up to 40 samples can be analyzed in one assay.