RADIOIODINATION AND QUALITY-CONTROL OF HUMAN THYROTROPIN FOR RADIOIMMUNOASSAY

This work reports the radioiodination of hyman thyrotropin (hTSH) in o ur laboratory (IPEN) and evaluates its quality in comparison with a co mmercial product. The radioiodination yield obtained in 20 experiments ranged from 18.5 to 56.3%, while the purification recovery ranged fro m 75.5 to 124.0% and the specific activity ranged from 1.01 to 3.10 MB q mu g(-1). The values for the distribution coefficient revealed in th e purification of radioiodinated hTSH ranged from 0.232 to 0.371. When tested concomitantly in the same radioimmunoassay system, the IPEN an d the commercial tracer presented parallel standard curves. A highly s ignificant correlation ion was observed between the quality control sa mples estimated through both curves (P < 0.001). These results confirm the quality of the hTSH radioiodinated at IPEN and suggest the acquir ement of self-sufficiency in this ''in vitro'' nuclear technology.