Removal of contaminating erythrocytes from human polymorphonuclear leucocyte preparations.

A simple discontinuous gradient of Percoll has been used to remove the erythrocyte (RBC) contamination in human polymorphonuclear leucocyte (PMN) preparations avoiding the possible adverse effects of differential lysis. Mononuclear cells are also removed leaving a preparation with a white cell purity of more than 99% PMN contaminated by less than 2% RBC. The yield of PMN was 40% with respect to whole blood. The metabolic response of cells prepared in this way was found to be comparable with PMN isolated using the technique of Böyum [3]. Small differences in the iodination response of the purified PMN were shown to be the result of the removal of RBCs rather than an inherent effect of the Percoll isolation procedure.