Study of microscopic experiment for freezing/vitrifying characteristics of CPA solution and cell suspension
Ma XH., Sun BB., Liu TQ., Cui ZF.
The freezing temperature for two kinds of CPA (cryoprotectant agent) solutions (DMSO and glycerol) at various freezing rates are measured by using the cryo-microscopic technique, and the freezing point and the vitrifying conditions are determined as well. Four freezing protocols are employed to cryopreserve the suspension solution of osteoblasts of SD big mice to investigate the factors influencing the viability of the frozen cells. The results of the experiment show that the freezing temperature of CPA solution is a function of the solution concentration and the freezing rate. High concentration of CPA solution and fast freezing rate are the necessary conditions to realize the vitrification. The properties of CPA solution, the protocols of freezing and thawing and the holding time are key factors to the cells recovery. This research is useful for searching for optimal freezing protocols for cell lines and tissues.