[Red cell preservation by freezing at -25 degrees C].

A method of red cell preservation by freezing at -25 degrees C is described. Glycerol is added to the red blood cells in the primary polyvinyl chloride plastic collection bag to achieve a concentration of 28 pr cent (W/V). The blood cells are concentrated by centrifugation and the supernatant glycerol is discarded. Glycerolized red cells are frozen and stored at -25 degrees C for 1 to 6 months. After thawing, Sodium chloride solutions are used to wash the red cells in the IBM Blood Processor 2991. The following parameters have been investigated before freezing, after thawing and washing and after storage of red blood cells at 4 degrees C for 24 hours: --Hemoglobin level --leukocytes and platelets --amount of 2-3 DPG and ATP. Preliminary data show that the in vitro quality of erythrocytes stored at -25 degrees C is well preserved for 4 months and that this simple method can be applied to blood preservation in any Blood Center.