ABSTRACT
BACKGROUND: Recent studies have shown that the optimal temperature at which the cord blood and the peripheral blood stem cells need to be cryopreserved is below -160 degrees C in a nitrogen tank. This study evaluated a domestic cryostorage cord blood processing bag (CBP set) made from poly (ethylene-co-vinylacetate) (EVA) recently produced by the Medi-Rution Company in Korea. METHODS: The domestic cryostorage bags was evaluated using 100 bags from Medi-Rution, which were divided into 3 different groups and compared with 20 bags produced by the Thermogenesis company from the United States as a control. In the first group, the mononuclear cells separated from the human blood sample were divided equally into the cryosolution using DMSO, auto plasma and RPMI media. The blood was preserved in 20 domestic bags and 20 bags produced by the Thermogenesis company. In the second group, the cells were stored in the cryosolution with either auto plasma or fetal bovine serum. In the third group, 20 bags were frozen at -70 degrees C before being stored in the nitrogen tank whereas the other 20 bags were frozen in a controlled refrigerator before being stored in the nitrogen tank at -196 degrees C. The bags containing the peripheral blood cells were stored in the nitrogen tank at vapor phase for a period of one year and evaluated for the rate of breakage during thawing, recovery rates and viability of the cell after thawing. RESULTS: None of the bags evaluated in this study showed any signs of breakage or leakage of the products. All three groups tested showed similar results regardless of where the bags were made, the composition of the cryosolution or the early freezing conditions. CONCLUSION: The CBP set cryostorage bags recently produced by Medi-Rution can be used to preserve blood cells at extremely low temperatures for a one year period without any significant breakage.