Is there evidence that samples are safe at -70C?
Spoiler alert - YES! If you've been following My Green Lab, you know that we coined the phrase '-70 is the new -80'. Adjusting your ultra low temperature freezer set point to -70C can reduce energy consumption by 30-40% and prolong the lifetime of a compressor-based freezer. For years we've been directing people to check out the incredible crowd-sourced document, that Dr. Kathy Ramirez-Aguilar at CU Boulder put together, of samples that have been stored at -70C. And now, thanks to our collaboration with the European organization EGNATON on the Freezer Challenge, we have been made aware of these two publications, which show sample stability at -70C for yeasts and molds, and the enzyme PON1. Furthermore, suppliers such as GE and Qiagen have updated their storage recommendations to -70C for certain reagents as well.
The community is still working on obtaining evidence for a wide range of samples - shout out to Martin Farley at Kings College and Amorette Getty at UC Santa Barbara for doing this work - but it's clear the evidence is mounting in favor of safe, sustainable sample storage at -70C.
If you choose to set your ULT freezer to -70C as part of the Freezer Challenge be sure to add your name and your samples to the Google doc! We would also be happy to add them for you - just email us at email@example.com.
Recent Nature article offers valuable advice for environmental and economic stability in the lab.
This week's edition of Nature features an article entitled, 'How Going Green can Raise Cash for your Lab'. The author details best practices from around the world for saving energy and reducing waste. Not sure how the Freezer Challenge can help save money for your lab? Read about the savings realized by our past winners, and learn about other ways labs are going green - and saving green - by clicking on the link above.