Technical Evaluation of a New Immunoradiometric and a New Immunoluminometric Assay for

carcinoma (DTC), serum thyroglobulin (Tg) can indicate persistent or recurrent disease. We describe two novel two-step assays designed to measure low Tg concentra-tions. Methods: We evaluated prototypes of the new IRMA, DYNOtest ® Tg-pluS, and the new immunoluminomet-ric assay (ILMA), LUMItest ® Tg-pluS. In the first step, a high-salt incubation buffer leads to dissociation of Tg-Tg antibody complexes in serum and is intended to reduce nonspecific interference and interference of po-tential Tg autoantibodies in the system. We studied recovery of human Tg (from thyroid glands) added to horse serum. We also studied 58 patients with DTC in whom Tg values under thyroid-stimulating hormone (TSH) suppression and TSH stimulation (without thy