中文摘要：

样本质量是体现生物样本库价值的关键,但是低温保存可能导致细胞凋亡及基因表达量的变化,影响样本质量。本文采用流式细胞术与实时荧光定量PCR（qPCR）的方法,研究了Hep-G2细胞在不同条件下冻存后凋亡及相关基因表达量。结果表明：低温保存影响Hep-G2细胞的成活率、凋亡情况及某些凋亡基因表达量。无论冻存过程中是否添加低温保护剂,低温保存都会对细胞的凋亡相关基因表达带来不同程度的影响。不添加保护剂冻存会导致细胞死亡,添加10%DMSO冻存会导致细胞凋亡,复苏培养24 h后细胞的成活率、凋亡情况与相关基因表达量基本与对照组水平一致。

英文摘要：

The quality of biospecimens is a very important factor of evaluating a biobank. Cryopreservation may induce apoptosis and changes of gene expression in cells. In this research the apoptosis profiles were assessed by flow cytometry and the expression of RNAs related to apoptosis were estimated by real-time fluorescent quantitative PCR（ q PCR） in Hep-G2 cells after cryopreservation. The results showed that with the addition of 10% DMSO or no cryoprotectant during cryopreservation,the cryopreservation progress made some impact on apoptosis and the expression of RNAs related to apoptosis in Hep-G2 cells. During cryopreservation,the cells were all dead with no cryoprotectant,but more cells apoptosis occurred with 10% DMSO. The cells could be recovered to normal level when the cells were recultured for 24 hours after cryopreservation.