Isolation of individual leukocyte types from peripheral blood.

Abstract A method of separating individual leukocyte types from peripheral blood with a system of Ficoll gradients is presented. Erythrocytes are removed first by centrifugation of the blood over a single dense (35 per cent) solution of Ficoll in a balanced salt solution. The granulocytes, lymphocytes, and monocytes are separated subsequently on a second Ficoll gradient. The latter consists of Ficoll layered stepwise in 0.5 per cent increments, the whole preparation being equilibrated for 24 hours. The method worked well for chicken and human blood with only minor modifications necessary to meet species differences. The over-all recoveries of the various cell types varied from 38 per cent for the granulocytes to 52 per cent for monocytes. From viability studies including assessment of phagocytic powers, motility, and exclusion of dye, the majority of cells appeared to be viable.