Colorimetric determination of creatine phosphokinase isoenzymes: detection in tissues and serum, and usefulness as an aid to diagnosis of myocardial infarction.

1. A colorimetric procedure for creatine phosphokinase (E.C.2.7.3.2.) isoenzymes suitable for routine laboratory use its described. The method utilizes a commercial product for visualization of CK isoenzymes in both serum and tissues. 2. The technic has been applied as an aid to the diagnosis of acute myocardial infarction. An intermediate migrating isoenzyme band (CK-MB) was detected in sera of 19 patients with clinical evidence of myocardial infarction and two patients with myocardial ischemia. The CK(MB) was absent in three patients presenting with symptoms suspect of, but not clinically confirmed as having myocardial infarction.