Optimized radiolabelling of pig granulocytes with indium-111 tropolonate

Standard labelling methods using 111In-tropolonate in plasma resulted in lower labelling efficiency (LE) with pig granulocytes than with human cells. Addition of acid-citrate-dextrose (ACD) to cell-free plasma in a ratio of 1:10 tripled the LE to a value which was not significantly different from that obtained in saline. Under optimized conditions, LE was 67 +/- 2% (mean +/- SE) with pig granulocytes, which remained lower than that obtained with human cells but was adequate for nuclear imaging studies of granulocyte deposition in the pig.