A kit for labelling erythrocytes or leukocytes with technetium-99m.

A pretinning method for labelling erythrocytes with technetium-99m (99mTc) in vitro has been developed using a kit which contains stannous chloride stabilized with gentisic acid. Labelling efficiency was 97.3% (SD 1.4%) for 80 patients. The method requires less time than the Brookhaven kit and results in a smaller volume for reinjection but provides equivalent clinical results. We have previously shown that leukocytes labelled with 99mTc using the same gentisic acid kit are clinically equivalent to those labelled with HMPAO; thus, the kit is versatile and cost-effective.