I have tried flash freezing in liquid nitrogen, then storing at -80; and slow freezing in -20, then in -80 surrounded by styrofoam, but in both cases cells weren't viable upon thaw. I was going to just try putting the tonsil in a DMSO solution but I was told that's not an option for tissue (??).
I need the lymphocytes so could I extract the cells and then try to freeze them instead of the whole tissue? Or do any of you use DMSO for tissue and it works fine? Any suggestions appreciated.