Method and kit for the selective labeling of red blood cells in whole blood with TC-99M

Claim 1

A method of labeling red blood cells with 99m Tc consisting essentially of: A. supplying a sample of whole blood, including plasma and the red blood cells to be labeled, to a container having therein under sterilized conditions a lyophilized stannous ion complex with a tin content of from 5-1000 μg together with a tin complex stabilizer and incubating the mixture for a sufficient time to permit some of the stannous ion complex to pass through the membranes of the red blood cells into the cells; b. subjecting the resulting suspension of red blood cells in plasma to the action of an oxidizing agent to convert substantially all of the stannous tin in the plasma to stannic tin; C. incubating the avove suspension with a chelating agent for both stannic and residual stannous tin in the plasma to form tin chelates; and D. incubating the resulting suspension with a source of 99m Tc pertechnetate ion, in a form in which the ion will pass through the cell membranes of the red blood cells into the red blood cells, for a sufficient period of time to permit the stannous ions within the red blood cells to reduce the technetium to a lower valence state in which it will not pass out of the cells through the cell membrane, thereby labeling the cells with 99m Tc.

Claim 2

A method of labeling red blood cells with 99m Tc consisting essentially of: A. supplying a sample of whole blood, including plasma and the red blood cells to be labeled, to a container having therein under sterilized conditions a lyophilized stannous ion complex with a tin content of from 5-1000 μg together with a tin complex stabilizer and incubating the mixture for a sufficient time to permit some of the stannous ion complex to pass through the membranes of the red blood cells into the cells; b. subjecting the resulting suspension of red blood cells in plasma to the action of an oxidizing agent to convert substantially all of the stannous tin in the plasma to stannic tin; C. incubating the avove suspension with a chelating agent for both stannic and residual stannous tin in the plasma to form tin chelates; and D. incubating the resulting suspension with a source of 99m Tc pertechnetate ion, in a form in which the ion will pass through the cell membranes of the red blood cells into the red blood cells, for a sufficient period of time to permit the stannous ions within the red blood cells to reduce the technetium to a lower valence state in which it will not pass out of the cells through the cell membrane, thereby labeling the cells with 99m Tc.