Long term storage at -80°C - (Feb/24/2014 )

Hi,

A Korean friend mentioned to me http://eng.genenmed.com/eng/bbs/board.php?bo_table=Products_01&wr_id=2&sca=CellFreezer which claims to allow cryopreservation of various cell lines at -80°C for up to two years.  So far I always stored my cells in liquid nitrogen.  Does anyone have experience with long-term storage at -80°C?  If you did so successfully, did you use any special cryopreservant that can be found in the US?

Thanks.

It is possible to store cells frozen by conventional methods at -80 for some period of time (many will last 6 months or more without too much loss of viability), but this is determined by the cell line, as some will not last long under these conditions.

I have stored some clones of HeLa and a couple of other lines at -80 for more than 2 years, and revived them with no problems, but this is unusual and definitely not recommended - the big problem is that you are selecting for a population of cells that can survive under those conditions if done repeatedly, which then makes them no longer the original cell line.

Storage in liquid nitrogen enables you to keep the cell lines for many years with no loss of viability, so I would still go for that over a system where you would need to keep track of, and thaw each line at least every second year.

Dear anntzer,

I had the Health Protection Agency (ECACC) in last year to give a presentation on basic techniques in cell and tissue culture. They covered cell freezing and the optimum way in then storing these frozen cells. The presenter said that is is essential to store cells below "the glass transition point" (-132oC) the temperature at which all water freezes and all biological activity ceases. Any temperature above this, even at -80oC chemical reactions will still take place which are damaging to cells. He presented evidence for this with a number of examples of cells stored at -80 and cells stored correctly at -196oC (liquid nitrogen). There were marked differences in the viability of the resusitated cells. 

As usual bob1 is correct when he states that you are exerting a selection pressure on your cells if stored at - 80oC i.e. selecting those who are more capable of surviving these higher temperatures. You may also see genetic drift (but I have no evidence for this).

Kindest regards

Uncle Rhombus