Effects of physiological isotonic cryoprotectants on living cells during the freezing-thawing process and effects of their uptake by electroporation: Sp2 cells in alginate-trehalose solutions

In the present study, effects of isotonic alginate and trehalose solutions on electroporated and unpulsed control murine myeloma cells (Sp2 line) during the freezing–thawing process were evaluated. To investigate the effects of these potential cryoprotectants, microscopic examination of cell suspensions in alginate–NaCl, alginate–trehalose, or trehalose media was performed during freezing–thawing at various cooling/warming rates (e.g., −1, −5, and −90 °C/min). It was found that, even at the lowest cooling rate, extracellular ice grains did not mechanically suppress cells in the trehalose‐substituted medium. Moreover, at all cooling rates, intracellular ice nucleation seldom occurred in the presence of extracellular trehalose. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(6): 511–523, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10105