Electrophoresis on cellulose acetate and chromatography on DEAE-sephadex A-50 compared in the estimation of creatine kinase isoenzymes.

We have compared two methods for separating the isoenzymes of creatine kinase in serum and measuring their activity: chromatography on diethylaminoethyl-Sephadex A-50, with both continuous and discontinuous gradient elution, and electrophoresis on cellulose acetate. Results by continuous and discontinuous gradient elution correlated well both for tissue extracts and sera. Electrophoresis on cellulose acetate is evidently less sensitive than the chromatographic method for detecting and measuring low activities of the isoenzyme designated MB. We describe how the isoenzymes may be separated by discontinuous gradient elution from microcolumns of the Sephadex and their activity rapidly quantitated by the Rosalki method [J. Lab. Clin. Med. 69, 696 (1967)], with a centrifugal analyzer.