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 (qPCR) 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 h after cryopreservation.