New creatine kinase assay kit for clinical analyzers- Know-How and techniques for reagent stabilization -
Journal Title: Journal of Analytical Bio-Science - Year 2013, Vol 36, Issue 4
Abstract
Creatine kinase (CK) is an essential enzyme that is present in various tissues like skeletal muscle, myocardium or brain, and it plays a crucial role in energy metabolism. During muscle or myocardial injury, CK is released from damaged cells, resulting in elevation of CK in the blood. Serum CK can be determined by the coupled enzyme reactions (HK-G-6-PDH assay), which finally detects the increase in the absorbance of NADPH. Based on HK-G-6-PDH assay, the Japan Society of Clinical Chemistry (JSCC) published a reference method of CK measurement for assay standardization across laboratories. In this method, experimental conditions and reagent prescription were optimized for routine analysis, but the preservation stability of the reagents was not well established. To provide commercial CK assay kits that can withstand long-term storage, it is desirable that JSCC prescription be modified in terms of stability. In this study, we focused on N-acetylcysteine (NAC) oxidation and G-6-PDH glycation as key elements that accelerate reagent deterioration. By applying reducing agents and minimized glucose concentration to the reagent, we developed a stable CK assay kit, CYGNUS AUTO CK.
Authors and Affiliations
Daisuke Kato
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