Separation of Free and Antibody-Bound Labelled Hormone by Kaolin in HGH Radioimmunoassay

Abstract

A rapid and easy separation of free HGH* from antibody bound HGH* is obtained with kaolin. Counting is performed on the total incubation volume. The HGH* which fails to adsorb to kaolin is in large measure damaged both physicochemically and immunologically. The serum protein concentration of the incubation mixture has little effect on the adsorption of free HGH* to kaolin. However, a sufficiently high concentration is needed to ensure that all the HGH*-Ab complexes will remain in the supernatant solution. 1 This work was supported by Grant No. 1013, Fonds de la Recherche Scientifique Medicale.