Granulocytic cryopreservation: further studies on the pathogenesis of impaired cellular function

The effects of different methods of purifying peripheral blood granulocytes on their functional capacity after cryopreservation have been studied. The standard method of isolating granulocytes by centrifugation through Lymphoprep sensitizes cells to damage induced by subsequent cryopreservation. Some of this damage occurs during addition of cryoprotectant and we describe how to add and remove dimethyl sulphoxide without impairing cell function. The granulocytic function that suffers most during cryopreservation is granulocyte migration. This impairment may be partially due to uncontrolled entry into the cell of calcium. In contrast the bactericidal capacity in vitro is not so greatly reduced and ability to reduce nitroblue tetrazolium redox dye even less so.