Preparation, characterization, and calibration of two fundamental reagents for the immunoradiometric (IRMA-125I) thyroid-stimulating hormone assay.

This study presents the development of an in-house immunoradiometric assay kit for the quantification of human thyroid-stimulating hormone (TSH), focusing on the preparation of two key reagents: calibrated TSH standards and a monoclonal anti-TSH antibody labeled with iodine-125 (125I). The radioiodinated tracer demonstrated a labeling efficiency of 96.8% and a radiochemical purity above 99%. The in-house standards showed excellent correlation with those of a commercial kit (R2 = 0.9996). These results support the potential use of locally developed reagents as cost-effective and reliable alternatives to commercial kits, pending further clinical validation.