Efficiency of in vivo labeling of red blood cells with 99mTc

The effectiveness of three commercial bone scintigraphic agents and freshly made stannous chloride in labeling erythrocytes with 99mTc was compared. Our results indicate that tin pyrophosphate is the agent of choice and that it is most effective when injected at least 15 minutes before the 99mTc-pertechnetate is administered. This technique of labeling red blood cells in vivo could be applied in performing blood pool studies.