|MadSci Network: Development|
Dear Diedre, There is no known limit to viability in LN2 (liquid nitrogen) if the cells were viable when frozen and the protocol for thawing doesn’t do any damage to the cells. This could be 20 minutes, 20 years, or 20 centuries as far as is known. The reason is that at –195.8 degrees centigrade, essentially all molecular activity stops so that the cell is very stable in storage over very long periods of time. This assumes that the material is never allowed to come out of the LN2 until time to thaw. Dr. Swanson
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