Li Xin, Zhang Yong, Chen Fang-ping
Department of Hematology, Xiangya Hospital, Central South University, Changsha 410008, China.
Hunan Yi Ke Da Xue Xue Bao. 2002 Dec 28;27(6):563-6.
To compare the different effects of the programmable cell freezer and the -70 degrees C mechanical freezer in the preservation of the combilical cord blood and to study the effects of magnetic activated cell sorting on cell biologic characters.
After separating the nucleated cells from the umbilical blood by the density gradient separation method, we used cryoprotectant to protect the nucleated cells and preserve them by two methods; one was using the programmable cell freezer to cool the cells and finally putting them to the liquid nitrogen, and the other one was directly preserving the cells in a -70 degrees C mechanical freezer. The cells were thawed after a month and tested for the viability and clonogenic ability. Cell recovery, clonogenic capacity and clonogenic recovery by the two cryopreservation methods were compared. Meanwhile, the CD34+ cells were sorted by the method of magnetic cell sorting from the umbilical cord blood, and the cell purity and recovery after sorting were analyzed by the method of fluorescence-activated cell sorting.
There were no significant differences between the two preserving methods in cell viability, cell recovery, clonogenic capacity, or colony recovery. The purity of the CD34+ cells was 88.3% and the recovery rate was 46.2% after the cell sorting. The cell viability and clonogenic capacity of the CD34+ cells were much higher than those of the CD34- cells.
The umbilical cord blood can be efficiently preserved by the two methods and highly purified CD34+ cells could be obtained by using the method of magnetic cell sorting. The procedure of cell sorting doesn't affect the viability and clonogenic ability. The study provides some evidence for clinical application of preserving the umbilical cord blood and transplanting CD34+ cells.
比较程序降温细胞冻存器与-70℃机械冷冻箱在保存脐血方面的不同效果，并研究磁性激活细胞分选对细胞生物学特性的影响。
采用密度梯度分离法从脐血中分离有核细胞，用冷冻保护剂保护有核细胞并通过两种方法进行保存；一种是使用程序降温细胞冻存器冷却细胞，最后放入液氮中，另一种是直接将细胞保存在-70℃机械冷冻箱中。一个月后将细胞解冻，检测其活力和克隆形成能力。比较两种冷冻保存方法的细胞回收率、克隆形成能力和克隆形成回收率。同时，采用磁性细胞分选法从脐血中分选CD34+细胞，并用荧光激活细胞分选法分析分选后的细胞纯度和回收率。
两种保存方法在细胞活力、细胞回收率、克隆形成能力或集落回收率方面无显著差异。细胞分选后CD34+细胞纯度为88.3%，回收率为46.2%。CD34+细胞的细胞活力和克隆形成能力远高于CD34-细胞。
两种方法均可有效保存脐血，采用磁性细胞分选法可获得高纯度的CD34+细胞。细胞分选过程不影响细胞活力和克隆形成能力。本研究为脐血保存及CD34+细胞移植的临床应用提供了一定依据。
