A Rapid, Centrifugation-Free Radioimmunoassay Specific for Human Chorionic Gonadotropin Using Glass Beads as Solid Phase

A simple, specific, rapid, centrifugation-free solid phase RIA for hCG has been developed. Purified γ-globulin isolated from antisera produced against hCGβ in rabbits is covalently linked to glutaraldehyde-activated aminopropyl glass beads. The entire assay can be completed within 3 h at room temperature. The sensitivity (1 ng/ml), precision (intra- and interassay variabilities, <10% and <15%, respectively), and specificity (0.4% cross-reactivity with LH) are comparable to other methods. The hCG levels determined by the present method show good correlation with those obtained by another RIA and by radioreceptorassay. The present method also provides the basis for the development of similar rapid and sensitive assays of other hormones.