Hi All – My lab’s -80C freezer failed over the weekend (as did the separate alarm system, so we weren’t alerted). The freezer wasn’t functional l for ~27hrs and the internal temp slowly increased from -80C to -1C. When discovered, all the contents were immediately moved to -20C. Clearly not ideal but I’m trying to determine just how catastrophic this is and whether I should prioritize my work with these samples differently based on this event. We had 3 years worth of work in there (almost 4,000 samples) and so much time invested in collection, processing, etc. The samples vary in type. We have 1) frozen field collected whole tissue (ticks and mosquitoes), 2) reserved supernatant from nucleic acid extractions (in AVL buffer), and 3) purified DNA and RNA. I mainly conduct pathogen testing (just research, not diagnostic) using qPCR and/or RT-qPCR with these samples. Despite the increase in temp, the liquid samples did still appear to be solid when they were transferred to the -20C, but I obviously couldn’t check every single tube or determine the extent to which tissue samples had thawed. I’m generally less worried about the purified nucleic acid than I am about the field collected tissue and the supernatant. We follow strict anti-RNase contamination procedures so, although a freeze/thaw cycle wouldn’t be ideal, purified samples are less worrisome to me than those with potentially active endogenous DNA/RNases. This is sound logic, correct? I’m also generally less worried about the impact on the DNA targets (and dsRNA target) compared to the ssRNA targets.

I suppose I’m essentially reaching out for guidance/advice (or optimistically, reassurance?). In your experience, how negatively impacted are these samples? Should I reprioritize or change work based on this event (i.e. not look for ssRNA targets in this batch of unprocessed field collected tissue but continue work as usual with purified DNA/RNA samples? What about DNA and dsRNA targets?).

Any insights would be appreciated.