Hi

We are regularly collecting mouse blood serum samples (clot for an 1hr, spin down & collect serum) in our lab for ELISA assays. We have come close to running out of space in our -80°C freezer and have experienced regular breakdowns of our freezers as well. On the other hand we have access to plenty of spare liquid nitrogen tanks (LNT) lying around.

1> I am wondering if it is safe to store our samples in LNT over a period of one-two years.

2> It seems to me that in a lab setting, LNT are cheaper to buy, maintain and much more reliable (no mechanical breakdowns). Then why do labs typically store samples in -80 °C? I understand that LNTs need refilling and sample retrieval is not as straightforward. Other than these, am I missing any major issues with LNT?

Thank you

Suyog