Iodination of thyroliberin by use of Iodogen.

In this method of labeling thyroliberin for radioimmunoassay, 1,3,4,6-tetrachloro-3 alpha,6 alpha-diphenylglycoluril (Iodogen) is used as oxidant. By cation-exchange chromatography and in response to antibody, thyroliberin so labeled behaved similarly to that produced by the conventional Chloramine-T method. Major advantages of the Iodogen method are its reliability, simplicity, and higher yield of stable RIA label in its most convenient (diiodinated) form.