Radioimmunoassay: A Method for Human Chorionic Gonadotropin and Human Luteinizing Hormone1

Abstract

Purified human chorionic gonadotropin has been radioiodinated to give an immunologically and biologically active product which possesses high specific activity. With this labeled hormone and an antiserum which is capable of reacting specifically with human luteinizing hormone and human chorionic gonadotropin, a sensitive and specific radioimmunoassay has been developed. Comparable results have been obtained when the content of luteinizing hormone in preparations differing widely in luteinizing and follicle stimulating activity have been estimated by the radioimmunoassay and the ovarian ascorbic acid depletion bio-assay. The assay is sufficiently sensitive to permit quantitation of normal amounts of luteinizing hormone in 0.1 ml of unconcentrated serum and urine. With the use of the assay, peaks in concentration of luteinizing hormone have been found in serum and urine of women near the time of presumed ovulation. (Endocrinology79: 10, 1966)