Sensitive radioimmunoassays using partially purified gamma globulins coupled to enzacryl (acrylamide polymer) solid support.

Enzacryl polythiolactone is a cross-linked acrylamide polymer with an active thiolactone group, capable of coupling to lysine, serine and tyrosine residues. Gamma globulins from antisera specific to human chorionic gonadotropin, carcinoembryonic antigen, alpha-foetoprotein or casein were isolated using Protein A Sepharose and were subsequently coupled to enzacryl. The resulting coupled antibodies were found to provide greater sensitivity and convenience in radioimmunoassay studies than conventional double antibody precipitation methods using the same antisera.