Storing cell lines long-term at -70C - (Jul/07/2010 )

Greetings, All.

A quick question - has anyone had any experience at storing cell lines at -70C as opposed to -140C ..?

I've usually stored such at -140C, but it looks like our access to a -140C freezer is going to be limited for a few months ... and so I was wondering if cell lines could be stored at only -70C, even if only for a limited time. I've done a little interweb snooping on the subject, and have come across very little - i.e. none - mention of storing cells at -70C. Does this mean it's simply not possible ..?

Comments/opinion etc. welcome!




Damian.

I've kept cells at -70 for about six months and been able to thaw without any problems.

Hey there, thanks for your reply.

If I may ask further, has this been the case with a broad range of cell types, or generally with more 'hardy' cells lines versus stable transfection clones, etc?

I'm primarily interested in DU145 and PC3 cells, neither of which I have had much experience in maintaining, and so I'm not sure how they'll fare under sub-optimal conditions.

Again, thanks for any feedback on the matter!

Don't store your cells at -70 °C longer than needed.
I observed some primary cells (HUVEC), that die even after 4 days at -80 °C (viability at thawing <10 %). Transfer the same lot of cells to N2 on the day after freezing leads to a viability >90 %.
In generally you can say, that primary cells are more sensitiv to -80 °C storage than cell lines. But even cell lines might have problems with long-term storage in 80 °C (e.g. Hek293 cells are fine after 1-2 weeks of -80 storage, but after 4 weeks the viability decreases to about 50 %, 8-12 weeks at -80 the viability of the same freezing batch is below 20 %).
Some cells like keratinocytes (primary and cell lines) are highly tolerable to -80 °C storage and nearly don't suffer even of one year storage at -80°C.
I don't have experiance with your cell lines, but just to make shure not to run in problems, try to avoid storage of cells at -80 °C longer than one week. I think that most cell lines even tolerate up to 1 month storage at -80 °C.

I agree with esgardis. I have no experience with the cells you mentioned, but you should avoid storing cells at temperatures above -130 degrees for long term storage (i.e. over a week). If possible, try to get a liquid nitrogen dewar to store your cells in. be careful to keep your cryovials in the vapour phase to avoid contamination of your cells. Also, keep an eye on the dewar to check when you need to top up with liquid nitrogen. Your cells should be fine until you can use the freezer again.