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 p-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.
