Radioimmunoassay of bile acids in serum

Four radioimmunoassay procedures are developed for the determination of glycine conjugated bile acids in serum. Antibodies to two primary bile acids, cholylglycine and chenodeoxycholylglycine, and to two secondary bile acids, sulfolithocholylglycine and deoxycholylglycine, were raised in rabbits after the acids were covalently linked to albumin by use of the carbodiimide reaction. Assay sensitivity for each of these bile acids is in the picomole range with the standard curve extending from 10-80 pmol. The concentration of bile acids in serum is increased in various states of liver disease and its measurement appears to be an extremely sensitive indicator of liver function.