Biochemical studies on cryopreserved granulocytes: possible explanations for the defects induced.

The functional capacity of normal; human granulocytes has been studied after cryopreservation by two different methods with dimethylsulphoxide as cryoprotectant. Both methods resulted in substantial disruption of organelle membranes and impaired cell function. Similar organelle disruption could be induced without cryopreservation following the addition of dimethylsulphoxide to cells, but the extent of this disruption was dependent on the temperature at which the dimethylsulphoxide was diluted out. The loss of cellular function also depended on the temperature and rate of dilution. We suggest that disruption of membrane organization is the mechanism underlying the loss of cell function induced by cryopreservation. Pending development of more successful methods of cryopreserving granulocytes, it is recommended that optimal preservation of functional activity would be obtained if the cryopreserved cells are thawed directly at 37 degrees C and the cryoprotectant diluted carefully and slowly.