Elution of human granulocytes from nylon fibers by means of repulsive van der Waals forces.

A novel method for the isolation of granulocytes from nylon fibers is described. It is modification of filtration leukapheresis based on cellular surface thermodynamics. The system takes into account both electrical and van der Waals forces. The elution buffer contains a chelating agent and a surface active agent which lowers the surface tension of the liquid to a value intermediate between that of the surface tensions of the nylon fibers and of the granulocytes. Thus, the attractive van der Waals interaction between the fibers and the granulocytes becomes a repulsion. This results in a two- to threefold increase in cell yield. Phagocytosis, candicidal activity, and oxygen consumption did not appear to be affected through the isolation procedure. By both light and transmission electron microscopy the isolated granulocytes appeared to be morphologically intact.