The place of reference materials in clinical enzymology.

Standardization embraces two concepts: achievement of a uniform standard of practice, or comparison with a standard of known or defined properties. In clinical enzymology the former concept can be equated with the adoption of recommended standardized methodology, which has had noteworthy successes in improving comparability of results. The use of enzyme standards or calibrators has received relatively little attention so far, but is increasingly important with the introduction of analysers which cannot readily utilize recommended methods. The main factor in the use of calibrators is that of commutability of calibrators and patients' samples between methods, which must be the subject of thorough experimental tests.