Effects of preparative technique on the rate of adoption of crawling-like movements by polymorphonuclear leukocytes

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.