低温保存过程中,冰晶的形成和生长是造成细胞损伤的主要因素之一.本文研究低温保护剂在降温过程中冰晶的生长规律,方法是应用低温显微镜系统,观察低温保护剂溶液的浓度及不同添加物对于冰晶生长和形状的影响,并利用差示扫描量热法(DSC)研究了溶液的熔融相变过程的变化.低温显微实验表明:低温保护剂溶液结晶形状、大小与溶液的浓度和添加溶质(糖或糖醇)有关,溶液浓度高,形成的冰晶小,对细胞损伤小,添加山梨醇的混合液冰晶形状细小,减轻了冰晶对细胞结构的物理损伤.DSC实验表明:在四种低温保护剂中5% Me2SO与山梨醇混合液(体积比)熔融温度最低,热焓值最小,溶液形成的冰晶最少,因此对细胞的低温损伤最轻.
Ice crystal formation is one of the factors that causes cell damage during cryopreservation process. Ice crystal will provide fun- damental information for the development of appropriate cryopreservation protocols. Effects of concentration and properties of solutions for the growth and shape of ice crystals were studied by using a cryomicoscopy system, and change on the solution of phase transition was ana- lysed by the use of differential scanning calorimetry (DSC) instrument. The experiment of cryomicoscopy demonstrates that the shape and size of the crystal of CPA are related to the concentration of the solution and the addition of the solute, and small ice crystals cause little damage to the cells with the high concentration, and reduce physical damage to the cellular structure with an appropriate ratio of sorbitol and Me2SO. Furthermore, DSC demonstrates that the temperature, enthalpy, and the crystal for the mixture of 5% Me2SO and 0.4M sor- bitol were much better than other three solutions, which means the injury of ceils has slightest.