Studies on the mechanisms of mammalian cell killing by a freeze-thaw cycle: conditions that prevent cell killing using nucleated freezing.

摘要: Normally a freeze-thaw cycle is very efficient method of killing mammalian cells. However, this report describes conditions that prevent cultured cells by nucleated freezing at -24 degrees C. Optimal protection from cell C was obtained in isotonic solutions containing an organic cryoprotectant such as dimethyl sulfoxide (DMSO; 10%, v/v), saccharide sucrose over broad concentration range 50 to 150 mM, and glucose. Glycerol also effective but other solvents were ineffective, although some cases they appeared protect membranes, while not protecting vital components. A wide variety structures killing, with trehalose being particularly effective. The degree resistance under these varied widely among different lines. If toxicity DMSO responsible for variability cryoprotection, it must have been due short-term, longer term, DMSO. Studies on the mechanism which are protected indicated neither vitrification medium nor concentrating components during involved. One model eliminated themore » mechanistic studies proposes solvent component acts fluidizing membranes thawing conditions, so any holes produced ice crystals propagating through can reseal process. In one mechanisms could act entering stabilizing intracellular Consistent this, promoted uptake labeled into cells.« less