Relative Efficiency and Interchangeability of Huggins and American Red Cross Red Cell Freezing Procedures

Cells glycerolized in a low salt medium (Huggins) and deglycerolized by agglomeration were compared to cells glycerolized in a high salt medium (ARC) and deglycerolized by a centrifugal procedure. Both agglomeration and centrifugal deglycerolization produce entirely acceptable products. The average total recovery by agglomeration is somewhat less (86 per cent) than by the centrifugal method (93 per cent). The osmolalities and hemoglobin concentrations are comparable. Cells glycerolized in a high salt preparation are very stable while unfrozen and are relatively unaffected by failures of refrigeration and can be refrozen. Cells glycerolized in low salt media may increase in volume with time and are variable in their stability to unfrozen storage and to refreezing. Sickle trait cells do not agglomerate satisfactorily and cannot be deglycerolized by agglomeration but can be deglycerolized by a modification of the centrifugal method. Container surfaces can adversely influence the freeze‐thaw hemolysis of high salt cells but appear to have no effect on the low salt preparation. Although cells glycerolized in high salt medium cannot be deglycerolized by agglomeration, the converse is possible. The standard 8.6M low salt glycerolizing solution did not permit optimal recovery by centrifugal wash. When cells were glycerolized in a Huggins low‐salt formula modified to contain 6.2M glycerol in 400 ml of solution, the frozen‐thawed cells could be deglycerolized by either agglomeration or centrifugation with good recovery.