A SENSITIVE RADIOIMMUNOASSAY FOR HUMAN CHORIONIC GONADOTROPHIN AND LUTEINIZING HORMONE

Abstract

SUMMARY: A quantitative assay for human chorionic gonadotrophin (HCG) based on the competition between isotopically labelled HCG and unlabelled HCG for HCG antibody is described. Antibody-bound HCG is separated from free HCG by precipitation with anti-γ-globulin serum. As a result of an immunological cross-reaction the assay also measures pituitary luteinizing hormone. It detects 0·001 i.u. HCG/ml. and normal urinary luteinizing hormone concentrations can be estimated without extraction. The specificity of the assay is discussed.