Henry Ford Hospital Medical Journal


Creatine kinase (CK) and lactate dehydrogenase (LD) are isoenzymes that have been measured in clinical laboratories for over 20 years; their separation has proved valuable in the diagnosis of myocardial infarction and other cardiac-related diseases. Although, historically, electrophoresis was the preferred method to measure both isoenzymes, there has been controversy over the best method for separating the CK isoenzyme. lon exchange chromatography has been used successfully to isolate CK isoenzymes, and the procedure was adapted to determine CK-MB activity in serum. New methods to quantify CK-MB have also been tested, including an automated column technique, the immunoinhibidon/ immunoprecipitadon technique, and immunoradiometry. In addition, new immunological techniques have recently been developed to analyze LD isoenzymes; the assay for LD-1 has already replaced electrophoresis. In time, specific assays for CK-MB will also be available. However, new techniques have not eliminated the need to order CK-MB and LD-1 as a battery and to employ appropriate timing and serial collection of samples.