Determination of Creatine Kinase in the Sera of Patients with Myocardial Infarction by a ρ-Nitrophenylglyoxal Method

Abstract

We have developed a new colorimetric method for the determination of creatine kinase (CK). This method is based on the reaction of creatine, formed enzymatically from creatine phosphate and ADP, with ρ-nitrophenylglyoxal (PNPG) under mild alkaline conditions to produce a coloured complex which absorbs maximally at 480 nm. This method was applied to the sera of patients with myocardial infarction. The results obtained by the PNPG method agreed well with the results obtained by other available methods for CK. However, the PNPG method was more convenient and less expensive than other methods and required a single chromogenic reagent. The PNPG method might be easily adapted to routine clinical application.