Abstract: Objective To compare the impact on stem cell quality between using modified cord blood separation method (modified method) and using traditional cord blood separation method (traditional method). Methods We developed a modified method, in which different centrifugation parameters were used according to the samples' volume. We collected QC vials' thawing data, which were processed within one year before and after the modification. Test results were compared between these two methods. Results In modified method group, volume after separation decreased from (25.68±2.03) mL to (22.53±4.24) mL (P<0.05). Red blood cells (RBC) removal rate rose from (75.87±11.84)% to (82.94±8.68)% (P<0.001). No statistic difference was observed in total nucleated cells (TNC) recovery, CD34⁺ cell recovery and CD34⁺ cell viability after thawing. In colony formation test, colony forming unit-granulocyte monocyte (CFU-GM) recovery were (60.00±32.52)% and (46.97±28.12)% in modified method group and traditional method group, respectively. The difference was statistically significant (P<0.05). Conclusion sThe modified cord blood separation method improved RBC removal rate and freezing product volume. After freezing, the stem cell showed higher potency in CFU-GM formation.

Key words: Cord blood, Modified cord blood separation method, QC vial thawing