[Comparative evaluation of the quality of leukocytes stored at -196 centigrades C in glycerol and polyvinylpyrrolidone (PVP)].
The authors assessed the phagocytic ability of granulocytes, the ability of blastic transformation of lymphocytes after phytohaemagglutinin (PHA) stimulation in vitro culture, and the viability and number of these cells before freezing and after thawing. No significant differences were found in the quality of granulocytes stored in cryoprotective medium containing 13% of glycerol or 15% of PVP. On the other hand, much worse results were obtained in both cases in comparison with previous investigations in which DMSO was used as the protective agent. It was observed also that lympocytes stored in a cryoprotective medium containing 15% of PVP were not significantly depressed and retained their ability of blastic transformation in vitro under PHA stimulation. Similar results were obtained using in previous investigations a cryoprotective medium with DMSO.