title: Radioiodination of human calcitonin using the Iodogen reagent.
abstract: A method is described for the radioiodination of human calcitonin using the Iodogen reagent. The tracer was purified by 2 successive gel filtrations. The first, using Sephadex G-10, resulted in the complete removal of free 125iodide as assessed by ascending paper chromatography. The second, involving Sephadex G-75, permitted the separation of the tracer from high molecular weight aggregates. Analytical RP-HPLC showed a slight proportion (13%) of a contaminating product, probably (sulfoxyl-methionine9)calcitonin. The final yield, after radioiodination, was found to be 42.7 +/- 5.5% and the tracer displayed a specific activity of 850 +/- 110 Ci/mmol. The effects of long-term storage of the frozen tracer were studied.
mesh_terms: D002116:Calcitonin / Q000378:metabolism*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002854:Chromatography, Paper; D006801:Humans; D007457:Iodine Radioisotopes / Q000378:metabolism*; D007553:Isotope Labeling / Q000379:methods*; D010084:Oxidation-Reduction; D011849:Radioactive Tracers; D011868:Radioisotopes; D014508:Urea / Q000031:analogs & derivatives*
chemical_list: D007457:Iodine Radioisotopes; D011849:Radioactive Tracers; D011868:Radioisotopes; C012385:1,3,4,6-tetrachloro-3 alpha,6 alpha-diphenylglycoluril; D014508:Urea; D002116:Calcitonin