15. Colony Forming Units-Megakaryocyte in Human Umbilical/Placental Cord Blood Are Extremely Sensitive to Freezing Injury(the 45th Annual Meeting)

Abstract

We found that the colony-forming units- megakaryocyte (CFU-Meg) in human umbilical/ placental cord blood (PCB) are sensitive to freezing injuries during cryopreservation. Mononuclear cells isolated from PCB were cryopreserved by the standard method used for the PCB banking. The recovery of CFU-Meg were less than other colony-forming cells. The cells were exposed to various osmotic stresses, cooled at different cooling rates, plunged into liquid nitrogen from different temperatures. Under these stresses, CFU-Meg were more sensitive than other colony forming cells. These results indicate that CFU-Meg are sensitive to freezing injury. This may be one of the reasons that platelet engraftment is slow in PCB transplantation.