ABSTRACT
The purpose of this investigation was to develop a simple colorimetric method for creatine kinase [CK]. The new method is based on the reaction of creatine, formed enzymatically from creatine phosphate and ADP, with different glyoxal compounds. Hydrated glyoxals, such as para-nitrophenyl, 2-thiophene, 4-biphenyl, 4, 4'-biphenyl, a-naphthyl, Beta naphthyl, para-chlorophenyl, and styryl were synthesized and allowed to react with creatine. Among the glyoxals, the 2-thiophene derivative was the best in terms of the stability and intensity of the colored complex which was produced under mild alkaline conditions. The complex absorbed maximally at 460 nm with an extinction coefficient of 1.56x 10[4] M[-1] Cm[-1]. This reagent was used to determine CK in the sera of normal human beings and patients with myocardial infarction. The results obtained were in agreement with those obtained by another available method for CK. However, this new method is simple, less time consuming and employs a single reagent for color development. Such a simple method might be of value in clinical laboratories with little access to sophisticated instruments such as autoanalyzers and spectrophotometers