Gel-chromatographic analysis of 99mTc-labeled human serum albumin prepared with Sn(II) as the reductant.

The labeling of human serum albumin (HSA) with 99mTc using Sn(II) as the reductant has been reinvestigated in view of the possibility of formation of Sn-Tc colloids. Preparations of 99mTc-HSA and mixtures of 99mTc-TcO-4 with Sn(II)Cl2 have been analyzed by means of gel chromatography using various gel matrices and eluents. No Sn-Tc colloids could be eluded from samples of 99mTc-HSA preparations. The percentage of labeling was about 90%. A comparative investigation of a number of gel-chromatographic systems for the detailed analysis of 99mTc-HSA has been made. It is found that a long column with Sephadex G-200 gives the best results.