Traceability and standardization of immunoassays: a major challenge

The clinical utility of immunoassay results is dependent on precision and trueness for the application of internationally agreed clinical protocols and common reference intervals and decision limits. The application of metrological principles to achieve traceability and standardization for these assays is being pursued to this end. Comprehensive measurement systems are available for a number of the total serum hapten assays routinely measured by immunoassays while current research is investigating the appropriateness of developing defined systems for the measurement of "free" hormone levels. The standardization or harmonization of assays for heterogeneous polypeptide hormones is also another area of research for these assays.