Programmed cooling method: The glycerol and Dimethylsulfoxide, as cryoprotective agents, were mixed with COC1 cells suspensions at different concentration, respectively.

• 程序降温法：以甘油和二甲基亚砜为低温保护剂，分别以不同的比例添加到含有细胞悬液的冻存管中。