Summary
Novelty: A competitive receptor binding assay for FK-506 and biologically active metabolites, derivatives and analogues thereof is disclosed.
Biology: The binding reagent is a specific FK-506 receptor protein either purified from the soluble cytoplasm of target cells of FK-506, particularly normal or transformed lymphocytes from freshly collected or established cell lines, or synthesized by recombinant DNA techniques. Solution phase and solid state assay systems are disclosed.