Accidental wrong concentration of DMSO for freezing - (Aug/13/2012 )
I recently mindlessly accidentally made a 20% DMSO/DMEM solution for freezing my cells, when normally it should be 10%. For endothelial cells. I just realized this, and it's been about 20minutes since I put it in -80C. Is there anything I could do? I can't imagine much by the time anyone replies, so I guess what I'm really asking is what I should expect. What is going to happen to them?
Thanks for your help.
They might be OK, the DMSO is an anti-nucleation compound to prevent the cells being lysed by crystal formation. If the tubes are still liquid (they should be for a while if you are freezing them correctly) then you could spin them down gently (100 rcf max) and re-suspend in the correct mix.
DMSO is toxic to cells at concentrations below about 0.5% (often much lower) and affects the cell membrane, so you may want to be careful when thawing them out.
The question you need to ask yourself is: do you still feel that it will be OK to use these cells knowing that they have undergone an event that could have compromised their integrity, and means that they may no longer be the same as the parent population?