ABSTRACT
Objective To explore the influence of cryopreservation by ladder-style freezing from low temperature refrigerator to liquid nitrogen on hemopoietic stem cell(HSC)transplantation.Methods From April 2001 to April 2006,31 cases treated with HSC transplantation were randomized to controlled-rate freezer-liquid nitrogen group(n=15)and refrigerator-liquid nitrogen group(n=16)in Department of Hematology of 1st People's Hospital of Yunnan Province.The hemopoietic reconstitution time was observed,and the viability of HSC was determined by trypan blue exclusion test in two groups.Results No significant differences were found in transfusion values of mononuclear cells(MNC)and CD34+ cells,rates of trypan blue exclusion and time of ANC0.05).Conclusion Cryopreservation of HSC can produce successful engraftment by ladder-style freezing which has cryoprotectant solution containing final concentrations of 3-percent hydroxyethyl starch,4-percent human serum albumin,and 5-percent DMSO,and its effect is the same as traditional controlled-rate method with 10-percent DMSO cryoprotectant.The new freezing procedure is faster and easier,and freezing cost is reduced.