- 80 broken - cells from broken -80 (Dec/22/2010 )

Hello All,

Some time back our -80 was broken for about 6-8 hrs and we had lots of cell banks stored in them! The vials were still frozen at the time we noticed and so we immediately transferred them to a different location. What is surprising is that: When we thaw these vials, the cell number is good and the Viability % is also not bad - around 85% and some were even 90%. But when we seed them onto the T75 flasks, the next day we see lots of cells dying and only 10% cells are attached. Is there an explanation to this phenomenon?

I am just curious to understand the science behind this.

Thanks,
Sci

First off... Your should store your cell banks at liquid nitrogen temperatures as -80 is not enough to completely stop metabolic activity (or something - cells certainly die after a period at -80) Some cell lines will last a few months (maybe up to 18 or so) at -80, but many will die after only a couple, especially primary and other non-transformed cell lines.

Freezing and thawing cells is a big shock, the cell membranes get damaged and the cells can take a while to recover from this, despite seeming to be OK when first thawed. There are all sorts of proteins called heat- or cold-shock proteins that are activated to protect the cell/tissue on heat/cold shock, many of which will cause the cell to apoptose if there is enough damage.

Those cell lines that mostly died off after 24 hours shouldn't be used for further experiments even if the attached cells proliferate well- you have just subjected the cell lines to a big selective event which means they are not necessarily the same as the parent line.