TECHNETIUM-99M-LABELED MOUSE-SPLEEN LEUKOCYTES - RADIOLABELING PARAMETERS

Bouse-spleen leukocytes were radiolabeled with 99mTc under neutral pH conditions. A low concentration of stannous chloride was used to reduce the sodium pertechnetate to a cell-binding lower-valence state. Cell radiolabeling was measured by radioactivity retention on glass-fiber filters. This procedure is quick and allows the assay of small aliquots of the radiolabeling reaction mixture. A stable cell radiolabel of 24.4% ± 5.2% was obtained which remained attached to the cell up to 27.5 h as measured by in vitro incubation in tissue culture medium. The viability of the cells after 99mTc-cell-labeling remains as high as the control. The radiolabeling efficiency of the cells with 99mTc was dependent on the concentration of cells and stannous chloride, but was independent of Na 99mTcO4 concentration. © 1979.