A Modified Differential Scanning Calorimetry Method for Determining Water Transport Properties in Biological Cells During the Freezing Process

A modified analytical and experimental method using differential scanning calorimeter (DSC) was applied to determine the cell water transport properties of human erythrocytes during the freezing process. Using DSC, samples containing human erythrocyte cell suspensions of human erythrocytes with different cytocrits were cooled to −40°C at slow cooling rates (5°C/min) after nucleation. It was shown that latent heat release from one unit mass of the cell suspension was a linear function of cytocrits (cell numbers), with a temperature-dependent slope and intercept. Based on the theoretical model, cell volumes were calculated from the slope and intercept at corresponding temperatures. Cell water transport properties (lpg,Ea) were next calculated by curve fitting of the cell volume change during the freezing process. The results revealed that, for human erythrocyte, Lpg (Tr = 273.15 K) is 0.10 ± 0.01 μm/min ċ atm and Ea is 279.1 ± 0.7 kJ/mol at the cooling rate of 5°C/min. For comparison, both DSC and cryomicro...