Morphological Change and Viability of Cells after Double Freezing and Thawing

Abstract

The viability of cells after freezing and thawing depends on kinds of cells, kinds and concentration of chemical additives, cooling and warming rates, minimum temperature, cycles of repetition of freezing and thawing, etc. In cryosurgery, destruction of diseased biological tissues in vivo by freezing, tumor cells could remain in the area away from the freezing probe if the temperature drop there is not sufficient to destroy the cells. However, the destruction of the cells can be promoted by the repeat of freezing and thawing. In this study, double freezing and thawing was imposed on a cell-sample to investigate the morphological change and viability of cells after freezing and thawing and the relation between both the characteristics. The characteristics were also compared between the 1st and 2nd cycles of repetition of freezing and thawing. Furthermore, the correlation between the cell viabilities after the 1st and 2nd cycles of repetition of freezing and thawing was determined on the basis of a mathematical model with reaction kinetic formulation of cell death. The correlation predicted from the mathematical model was compared with the experiment to clear the effect of the double freezing and thawing.