Abstract
Cryopreservation by vitrification procedure produces vitrified state both out- and inside of cells. Although vitrified state outside the cells is constructed by solidificatiion of pure vitrification solution (VS), the vitrified state inside the cells that allows for successful cryopreservation may be constructed with different manners among individual procedures depending upon differences of interaction between biological materials and VS. In case of rye protoplasts, vitrified state inside the cells, that is produced by mere osmotic dehydration of cells by VS treatment without permeation of VS inside the cells, may allow for high survival. In case of bovine blastocysts, vitrified state inside the cells, that is produced by osmotic dehydration by VS as well as partial permeation of VS inside the cells, may be prerequisite for high survival. In case of mouse blastocysts, vitrified state inside the cells, that is produced by permeation of VS in almost equilibrated state with little effects of dehydration, may produce high survival. It is suggested that the differences of vitrified state that allows for high survival may depend upon differences of the dehydration tolerance among specimens. Thus, appropriate VS should be chosen on the basis of difference in the dehydration tolerance among the specimens.
