Cell labeling: radiation dose and effects

An editorial is presented which considers some aspects of the problems associated with studies utilizing radioactively labeled blood cells. For many years, nuclear medicine researchers have sought agents to successfully label cellular blood elements with radionuclides to determine the fate of the cells by both external imaging and in vitro measurements. The labeling procedure must have no effect on functional activities of the cells, and there must be little or no spontaneous release of the radioactive label. Several different radioactive labels (Cr-51, Tc-99m, In-111) have been used, and are discussed in this editorial