A simplified in vitro method of red blood cell labelling with 99Tcm using whole blood

: A modified method of in vitro labelling of red blood cells with 99Tcm using whole blood is presented. Blood samples from patients with normal blood counts were used. First, the blood sample was exposed to a low concentration of stannous ions (0.02-0.4 micrograms/2 ml blood), citrate phosphate glucose solution was then added followed by 99Tcm pertechnetate. A high labelling yield of greater than 90% was achieved in a maximum of 30 min.