Receptor assays in the clinical laboratory

Objective: To review the relative advantages/disadvantages of receptor assays versus immunoassays. Review of current literature results: The history of immunoassays is evaluated. Current shortcomings are emphasized. The present and future role of receptor assays is assessed. Conclusion: The author predicts a shift away from immunoassays to receptor assays for certain analytes such as Vitamin B12, folic acid and drugs that undergo extensive metabolism.