Studies on granulocyte preservation. III. Effect of agitation on granulocyte concentrates.

The effect of agitation on granulocyte storage was examined. Granulocyte concentrates were obtained as buffy coats from fresh blood by centrifugation and stored for up to 48 hours at 22 degrees C with or without horizontal agitation (80 rpm). The cell counts, mean cell volumes, morphologic changes, phagocytosis, and bactericidal activity of the stored granulocytes did not differ significantly. However, chemotaxis was maintained better in granulocytes that were agitated. At 48 hours, the ability of unagitated cells to adhere to both immunoglobulin-coated and uncoated glass surfaces increased, and clumps were observed on the surfaces. These results seem to be related to the decrease in chemotaxis. The pH of unagitated sedimented cells was more acid. To avoid the decrease of this local pH, stored granulocytes need gentle agitation.