Abstract: Objective The glycerolization process for preparing frozen red blood cells(RBCs) was improved, and washed RBCs were tested and analyzed. Methods Twenty samples of suspended red blood cells (SRBCs) (one unit) stored at 4℃ for 7 days were randomly divided into two groups. In the process of glycerolization, 57% compound glycerol reagent was diluted to 40% glycerol solution with 0.25 mol/L glycine solution in isotonic saline, and the glycerol concentration was reduced, while other processes remained unchanged in the experimental group; 57% compound glycerol reagent was added in the control group. The frozen RBCs prepared in the two groups were stored at -80℃ for 1 month, then, were thawed for glycerolization. The quality indexes of frozen and thawed/deglycerolized RBCs (DRBCs) in the two groups were compared and analyzed. Results The indicators of free hemoglobin and residual glycerol in both groups were in line with the Quality Requirements for Whole Blood and Component Blood (GB18469-2012). Free hemoglobin (0.60±0.05), residual glycerol (0.56±0.23), total glycerol in DRBCs (0.82±0.05), and hemolysis rate (0.33±0.10) in the experimental group were significantly decreased compared with the control group, with statistical difference (P<0.05). The ATP (5.34±0.35) and 2,3-DPG (538.40±59.96) in the experimental group were significantly higher than those in the control group (P<0.05). The recovery rate of DRBCs in the experimental group (86.9±2.18) was not significant difference compared with the control group (P>0.05). The osmotic fragility test of erythrocytes in the experimental group showed the sodium chloride concentration at the beginning of hemolysis (4.28±0.33) was significant difference (P<0.05), while the sodium chloride concentration at the complete hemolysis (3.08±0.27) was not significant difference (P>0.05). Conclusion During the glycerolization process of preparing frozen red blood cells, DRBCs prepared by using 40% glycerol diluted with glycine solution as cryoprotectants were stored for 1 month. Compared with the control group, the residual glycerol, total glycerol in DRBCs, serum free hemoglobin and hemolysis rate were significantly decreased, while the levels of ATP and 2, 3-DPG were significantly increased. This improved the product quality of frozen red blood cells.

Key words: Glycine, Glycerolization process, Frozen red blood cells