In vitro study on cryopreservation of peripheral blood stem cells with uncontrolled freezer

Objective: To evaluate the effects of cryopreservation of APBSCs in −80°C un-controlled freezer and liquid nitrogen, and to search for the efficient combined cryoprotectant and the highest cell concentration for cryopreservating peripheral blood stem cell (PBSC). Methods: To compare the effect of three combined cryoprotectants, evaluation of in vitro proliferative capacity by colony-forming unit-Granulocyte-macrophage (CFU-GM) and burst-forming Unit-erythroid (BFU-E) assay, immunophenotyping for CD34 + /CD38 − cells by FCM, and viability assessment by trypan blue exclusion were performed. Results: The cryoprotectant 10%DMSO+HES+auto-Plasma resulted in the highest recovery rates. CFU-GM and BFU-E were (78.7±9.8)%, (69.8±14.1)%, respectively. The recovery rates of CFU-GM and BFU-E in A/C groups were (68.3±6.2)%/ (65.8±7.2)% and (63.4±9.7)%/ (60.4±10.5)%, respectively. The recovery rates of CD34 + /CD38 − cells and cell viability with the three combined reagents were 90% and 80%, respectively. Conclusion: 5%DMSO+ HES+auto-PLASMA is an ideal combined cryoprotectant for cryopreserving PBSC. The cell concentrations may be cryopreserved at 4×10 8 ml −1 .