Characteristics of monoclonal antibodies against human thyroid peroxidase for use in immunoaffinity chromatography and immunoassays

Two types of monoclonal antibodies (MABs) against human thyroid peroxidase (TPO) have been obtained, which interact with spatially separated conformational epitopes of the antigen (K _a values are in the range 10⁸–10⁹ M^?1). The binding site of MAB F8 is in the immunodominant region of the TPO molecule, in the vicinity of the autoantigenic determinants, whereas the epitope specific for MAB A1 lies outside this location. Both MABs retain the ability to form immune complexes after solid-phase immobilization and chemical modification with a biotin derivative. The above properties suggest that MABs A1 and F8 may be used in immunoaffinity chromatography (isolation and purification of TPO from natural sources) and immunoassays for determinations of TPO (in biological fluids) and TPO autoantibodies (in human blood serum).