ISSN Online: 2377-424X
International Heat Transfer Conference 12
Microbehavior and Intracellular Ice Formation during Freezing of Biological Cell
Sinopsis
The accurate prediction of intracellular ice formation (IIF) during freezing of biological cell is greatly important for determining life/death of living system in cryopreservation. In this paper, by combining in vitro experiment and analysis, the mechanism of IIF has been studied in relation to the contraction of the cell membrane. In the experiments, freezing process of wheat protoplasts suspending in isotonic solution or silicone oil was microscopically observed, changing the pre-contraction fraction of the cells using osmotic manipulation. Firstly, the experimental results indicated the occurrence of precedence freezing outside the cell, water permeation
through the cell membrane and the intracellular ice formation at supercooling stage. Secondly, the probability of IIF decreased with increasing pre-contraction fraction of the cell, since the inoculative action of the external ice through the cell membrane reduced. Thirdly, a physicochemical model of IIF taking account of the contraction effects was proposed. Summarizing these results, the mechanism of IIF was discussed with cooling rate.