Abstract
Cryoprotectants are used to improve the viability of biological cells in cryopreservation of the cells. However, the details of the mechanism of protection of cells by cryoprotectants are not yet clear. In this study the process of solidification of human red blood cell suspensions was investigated microscopically. Three kinds of solutions were used: physiological saline, and physiological salines with 2.00M dimethyl sulfoxide (DMSO) and with 20.0wt% dextran (Dxt). Addition of DMSO or Dxt to physiological saline caused the cellular ice crystal to have secondary arms and a morphologically complicated structure, and simultaneously, facilitated to deform flexibly the freezing interface in response to the cells. This result suggests that DMSO and Dxt have an effect to decrease the mechanical action on the cells.
