Immunochemical determination of CK-MB isoenzyme in human serum. II. An enzymic approach.

A novel immunochemical technique for a specific enzymic determination of the myocardial isoenzyme of creatine kinase, CK-MB, involves determination of B-subunit activity of a specimen in which the M-subunit activity has been inhibited by specific antibodies to the M-subunit. Interfering activities from CK-BB isoenzyme, atypical forms of creatine kinase, and adenylate kinase are eliminated by using a blank tube in which all the M-subunit-containing isoenzymes have been removed by a specific immunoprecipitation step. The assay is convenient, linear, and reproducible, and results compare well with those by agarose electrophoresis.