Abstract: In this research, the growth characteristic of mouse embryonic stem cells (mESCs) in dynamic culture was studied. With the addition of ascorbic acid, the significantly increasing time of β-galactosidase activity which was related to senescence delayed from day 6 to day 10. At the same time, intracellular reactive oxygen species level in the experimental group was lower than that in the control group, and there was a significant difference between the two groups at day 8 -day 9. Further analysis showed that the total expansion fold of mESCs and the expansion fold of SSEA-1+cells were 53.9±1.5 and 51.9±6.3 at day 8, respectively, both of which were significantly higher than those in control group without ascorbic acid, respectively (41.3±0.9 and 40.1±3.9). These data proved that ascorbic acid can reduce the level of intracellular reactive oxygen species significantly, improve the aging state of mESCs obviously and promote ex vivo expansion of mESCs. The research provides a new way to solve the aging problem of ESCs in the process of enlarged culture.

Key words: embryonic stem cells, ascorbic acid, dynamic suspension culture, cell aging