Differentiation between steroid hormone receptors CBG and SHBG in human target organ extracts by a single-step assay.

The steroid complexes of (plasma) corticosteroid-binding globulin can be distinguished from intracellular steroid-receptor complexes by agar electrophoresis at low temperature in neuraminidase-treated tissue extracts. With this method, the presence of progesterone receptor has been demonstrated in heavily plasma-protein-contaminated human uterus "cytosol", but not in human mammary carcinoma extracts. SHBG and "basic" receptors for estradiol and dihydrotestosterone in human uterus cytosol could also be assayed simultaneously.