Exposure to dimethyl sulfoxide at 37 degrees C prior to freezing significantly improves the recovery of cryopreserved hybridoma cells

Standard cryopreservation protocols recommend the use of dimethyl sulfoxide (Me2SO) at moderate temperatures only (room temperature, 4 degrees C) due to its toxicity which appears to be potentiated by warm temperatures. In the present study, we asked whether a transient increase in temperature during membrane sealing of cryovials affects the cell viability. We show here that the cell viability of hybridoma cells and Schwann cells was not reduced following membrane sealing of cryotubes. On the contrary, incubation of cells at 37 degrees C in Me2SO-containing medium prior to freezing significantly stimulated the viability of cryopreserved hybridoma cells, whereas the viability of Schwann cells remained unaltered. We conclude that the exposure of cells to Me2SO at elevated temperatures does not necessarily reduce cell viability and that contrary to this, cell type-specific, beneficial effects of Me2SO could be observed.