Related Experiment Video
Updated: Jun 25, 2026
Flash-and-Freeze: A Novel Technique to Capture Membrane Dynamics with Electron Microscopy
Published on: May 1, 2017
Membrane hydration correlates to cellular biophysics during freezing in mammalian cells
Saravana K Balasubramanian1, Willem F Wolkers, John C Bischof
1Department of Mechanical Engineering, University of Minnesota, 111 Church Street SE, Minneapolis, MN 55455, USA.
Abstract:
Cell survival during freezing applications in biomedicine is highly correlated to the temperature history and its dependent cellular biophysical events of dehydration and intracellular ice formation (IIF). Although cell membranes are known to play a significant role in cell injury, a clear correlation between the membrane state and the surrounding intracellular and extracellular water is still lacking. We previously showed that lipid hydration in LNCaP tumor cells is related to cellular dehydration. The goal of this study is to build upon this work by correlating both the phase state of the membrane and the surrounding water to cellular biophysical events in three different mammalian cell types: human prostate tumor cells (LNCaP), human dermal fibroblasts (HDF), and porcine smooth muscle cells (SMC) using Fourier Transform Infrared spectroscopy (FTIR). Variable cooling rates were achieved by controlling the degree of supercooling prior to ice nucleation (-3 degrees C and -10 degrees C) while the sample was cooled at a set rate of 2 degrees C/min. Membranes displayed a highly cooperative phase transition under dehydrating conditions (i.e. NT=-3 degrees C), which was not observed under IIF conditions (NT=-10 degrees C). Spectral analysis showed a consistently greater amount of ice formation during dehydrating vs. IIF conditions in all cell types. This is hypothesized to be due to the extreme loss of membrane hydration in dehydrating cells that is manifested as excess water available for phase change. Interestingly, changes in residual membrane conformational disorder correlate strongly with cellular volumetric decreases as assessed by cryomicroscopy. A strong correlation was also found between the activation energies for freezing induced lyotropic membrane phase change determined using FTIR and the water transport measured by cryomicroscopy. Reduced lipid hydration under dehydration freezing conditions is suggested as one of the likely causes of what has been termed as "solution effects" injury in cryobiology.
Related Concept Videos
01:26Membrane Fluidity
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
01:23Membrane Fluidity
01:34Fluid Mosaic Model
01:19Fluid Mosaic Model
03:12Freezing Point Depression and Boiling Point Elevation
The boiling point of a liquid is the temperature at which its vapor pressure is equal to ambient atmospheric pressure. Since the vapor pressure of a solution is lowered due to the presence of nonvolatile solutes, it stands to reason that the solution’s boiling point will subsequently be increased. Vapor pressure increases with temperature, and so a solution will require a higher temperature than will pure solvent to achieve any given vapor pressure, including one...
02:45Responses to Heat and Cold Stress