Labelling of Human and Rabbit Platelets with 111Indium-Oxine Complex

Abstract

Platelets suspended in buffer were labeled with 111In-oxine. In the isolation procedure platelets and a fraction of the erythrocytes [RBC] were processed simultaneously, whereby the RBC served as a supporting cushion in centrifugation steps. Various factors which influence labeling effectiveness were examined, and the method''s utility was estimated by in vivo studies in rabbits. Platelet concentration of more than 800 .times. 109/l and oxine concentration of approximately 6 .mu.g/ml in a plasma-poor system (platelet transfer from plasma to buffer without further washing steps) yielded high labeling efficiency. If the platelet isolation yield was to be large, slight erythrocyte-leukocyte contamination must be accepted and was apparently permissible. In vivo investigations of 5 rabbits showed in vivo platelet recoveries from 61-74% and mean survial times from 69-110 h. The method of platelet isolation and labeling is apparently gentle.