Abstract
Various component steps of several "standard" techniques for separating polymorphonuclear leukocytes (PMN) from whole blood were tested for their effects on the rate at which these cells exhibit crawling-like movements when suspended in 100% plasma. The rate was depressed by excessive centrifugation, excessive agitation, erythrocyte lysis techniques, prolonged preparation time and one type of separation medium used. More than 95% of PMN in all preparations excluded the dye Trypan blue. The rate at which PMN exhibit crawling-like movements in plasma could be a sensitive index of the viability of these cells.