[Improvement of inter-laboratory imprecision in enzyme measurements]

The traceability chains of the enzyme measurement system were established based on technological advances in instrumentation and reagent systems. The values assigned in reference materials (Japan Certified Enzyme Reference Materials; JCERM) were transferred to daily laboratory analysis via enzyme calibrators included in industrial reagent kits. The imprecision between laboratories was then minimized to within 4 percent in six enzymes, AST, ALT, LD, ALP, CK and gamma-GT.