Cell affinity investigations with lipophilic 99mTc-complexes in labelling of leucocytes

After separation of leukocytes from whole blood with 'Dextran'-sedimentation in the leukocyte population is a mixture of granulocytes, monocytes and lymphocytes with a contamination of nearly 4-5 platelets and 2-3 erythrocytes per leukocyte. The cell affinity of 99mTc-HMPAO and 99mTc-DPD to this cell-mixture was measured by scanning of discontinuous dense gradient-column. The results show, that at both radiopharmaceuticals 68%±3 of activity is bound to the granulocytes. This means, that both removing of residual erythrocytes and platelets and the separation of pure granulocytes from mixed leukocytes before labelling procedure is not necessary. We conclude from this results in clinical routine studies. (orig.)