IMMUNORADIOMETRIC AND TWO-SITE ASSAY OF HUMAN FOLLICLE-STIMULATING HORMONE

Abstract

SUMMARY An immunoradiometric assay for human follicle-stimulating hormone (FSH) is described. A non-specific antiserum to human FSH was purified by incubation of the antiserum with human luteinizing hormone and thyroid-stimulating hormone before its reaction with an immunoadsorbent containing human FSH. The specific antibodies to human FSH isolated on immunoadsorbent were iodinated and used for the FSH assay. The sensitivity of the assay was improved by the extraction of plasma FSH onto antibody-coated polyethylene tubes before its reaction with iodinated FSH antibodies producing a two-site assay. Optimal conditions for the preparation and use of antibody-coated tubes in such a procedure are described. Using serial extraction a sensitivity of 11 pg/ml (0·1 mu./ml) was achieved. There was good agreement between the results obtained with this method and those obtained with radioimmunoassay. The advantages of the increased sensitivity of this new method are discussed.