long term storage of cells at -80 - (Feb/19/2012 )
Hi every one,
I stored some cells in 90% FBS cell freezing medium at -80 freezer over a year ago. I revived them recently, cell viability was 90% and cell growth was normal. we always transfer friezed cells to -180 for long term storage. does any one know if cell characteristics will stay constant after long time storage at -80?
Cells should not be stored long term at -80 as they do slowly die off. It will depend on which cell line you are using as to how long they will last in the -80, but most cell lines will not last much more than a year at -80. There are apparently still some enzymatic processes that can continue at -80 which reduce the viability of the cells. Ice crystal formation, which is the biggest killer of frozen cells also is more likely to occur.
look at it this way - the 10% of your cells that didn't survive - which 10% were they? Could you be artificially selecting for a cell population that can survive this particular stress? How would this selection affect your results? how similar are these cells now to the parent line?