Preparation of 111In leukocytes after hemolytic removal of erythrocytes

An optimized procedure is described for isolation and high-efficiency radiolabeling of leukocytes using 111In-oxine. The chief advantages over conventional methods include virtually no loss of leukocytes during washing and separation steps; a significant reduction in the time required to prepare leukocytes for radiolabeling compared to non-hemolytic preparations; a 28% increase in the average labeling efficiency obtained using 111In-oxine; > 95% cell viability as measured by the trypan blue exclusion test; elimination of contaminating red blood cells from the leukocyte pellet prior to labeling; and 80% survivability at 15 min post injection (measured as per cent of blood activity on leukocyte fraction). (author)