Comparison of different cryopreservation methods of human embryonic stem cells.

【Objective】 The study compared the recovery rate of human embryonic stem(hES) cells after cryopreservation using various protocols and established an effective method for hES cells cryopreservation according to the clinic standards.【Method】 hES cells were frozen with slow-cooling protocols,vitrification protocols with open pulled straws(OPS) and vitrification protocols with closed sealed straws(CS).The recovery rates of the three methods were compared,and Immunocytochemistry was used to observe the expression of OCT-4 on hES cells after cryopreservation.【Result】 The recovery rate was(97.5±5.0)% by vitrification with OPS and(96.7±5.8)% by vitrification with CS,which was much higher than the rate of slow-cooling,(25.7±4.1)%.Positive expression of OCT-4 in the most cultured cells was detected by immunocytochemistry.【Conclusion】 Vitrification by OPS and CS methods are reliable and effective for the cryopreservation of human embryonic stem cells.