h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

What is the difference between a sample stored frozen at -70(Celcius) and -196(Celcius). Can you transfer cells (for example) stored at -70 to -196 without damage.

Isn't the freezing/melting point of nitrogen or oxygen in between? If there's any free N2 or O2 about then it might have some kinda effect.

But I don't know.

You can certainly transfer cells from -70C to -196C (ie, from an industrial freezer to liquid nitrogen). It was the standard way of storing cells in the dim and distant past when I was a (pretty hopeless) cell biologist - first freeze them to -70C, then move them to liquid nitrogen, as immersing them straight into liquid nitrogen would kill them. The lower the final temperature, however, the longer the cells can be stored in a viable state (assuming they survive the freezing!) Even I managed to retrieve cells from liquid nitrogen and grow them in culture