A comparison of two creatine kinase MB determinations: a chromatographic versus an immunological method

Determinations of the MB isoenzyme of creatine kinase by ion-exchange chromatography and by an immunological method show good overall correlation in plasma of patients with proven infarctions, r=0.98. In analyzing myocardial tissue samples, unexpected discrepancies are found between these two methods. An as-yet-unidentified creatine kinase, in chromatography behaving as MM and immunologically undistinguishable from MB, is found.