外胚间充质干细胞的体外分离和鉴定

目的 :探讨SD大鼠外胚间充质干细胞的超微结构及经体外长期传代后变化程度。方法 :电镜分析组织细胞的超微结构 ;用流式细胞仪检测传代细胞的干细胞特异性标志CD57和P75的变化。结果 :细胞增殖旺盛 ,代谢活跃 ,处于未分化状态。P0 -P5期间 ,CD57和P75阳性细胞的比例没有明显降低 ,从P6开始 ,下降迅速 ,至P8-P10 期间已不可测。结论 :①干细胞可以在体外维持生长并增殖 ;②长期培养后 ,干细胞比例下降 ,甚至消失 ,这可能存在两种原因 :其一 ,干细胞经过体外培养已经完全分化了 ,失去了原有的表型 ;其二 :干细胞仍然存在 ,但缓慢增殖 ,被增殖迅速的瞬时扩增细胞稀释 ,以至无法检测

In Vitro cultivation and identification of ectomesenchymal stem cell

Objective:To assess the ultrastructure of the SD rat ectomesenchymal cells and the level of after continues propagation.Method: The ultrastructure of the ectomesenchymal cells were studied by TEM ;each passengers were analyzed the specific marker CD 57 and LNGFR P 75 by FCM.Result: The dates suggested that most of ectomesenchymal cell maintained undifferentiated and active saatus and showed that CD 57 and P 75 cells did exist before P 5,but deduced from P 6 ,and became undetectable from P 8 to P 10 .Conclusion: The experiments confirmed the survivial ability of stem cell in Vitro ,but arise the arguments for vanquished stem cell.We believe there are two possibilities: First,the stem cells completely differentiated and lost CD 57 and P 75 phenotype; Second: it proliferated along with other TACs ,but became rare population so can not be approach.