-70 ˚C/-80 ˚C Comparison Pilot Program
Trying to convince your lab that samples don't have to be stored at -80 ˚C?
We are, too! We have an ongoing pilot comparing samples stored at -20 ˚C, -70 ˚C, and -80 ˚C to show our lab members that -80 ˚C may not be the only option for long-term storage that is safe and reliable for samples.
What are Green Labs Pilot Programs?
BBE is providing funding for sustainable pilot programs at Caltech! If you or your lab has a sustainable project you would like help getting off the ground, please fill out an Application Form. For reference, here is an example form for the Lomi Composting project. Submissions officially open in June 2023.
-70 ˚C/-80 ˚C Comparison Pilot Program
Green Labs is calling for samples for a student-led study comparing samples held at -20 ˚C, -70 ˚C and -80 ˚C in the Chen Freezer Farm.
Samples from various labs will be tested and compared at intervals over a period of up to 5 years. We are testing the assumption that "colder is better" in terms of ultra-low temperature storage of samples.
We hope that by conducting a controlled study at Caltech, we can provide evidence for labs to change their -80 ˚C freezers to -70 ˚C, ensuring an energy savings of up to 30%! This "chill-up" will also reduce the number of defrosts your freezer requires each year, and reduces the wear and tear on your freezer! Here are some additional resources suggesting that -70 ˚C is a safe storage temperature for many kinds of samples.
If you are interested in contributing a sample, please email us at greenlabsinfo@caltech.edu or fill our this Google Form!
Update: Since September 2023, we have stored and tested samples of glycerol bacterial cultures, animal cell lines, and protein.
Preliminary results show that in -70 ˚C compared to -80 ˚C : bacterial biomass yield and DNA yield are consistent; and animal cell death fraction (apoptosis) is constant; and protein function and integrity is unchanged. By the start of 2025, we hope to have a finalized writeup to share, so stay tuned!
Our plan: Conduct a controlled study to provide evidence that -70 ˚C is a safe temperature for long-term storage. Furthermore, adjusting temperatures from -80 ˚C to -70 ˚C ensures an energy savings of up to 30%! This "chill-up" will also reduce the number of defrosts your freezer requires each year, and reduces the wear and tear on your freezer! Here are some additional resources suggesting that -70 ˚C is a safe storage temperature for many kinds of samples.
If you are interested in contributing a sample, please email us at greenlabsinfo@caltech.edu or fill our this Google Form!
Is keeping our ultra-low temperature freezer at -70 ˚C just as good as -80 ˚C? Short answer: YES! Here are some references to support our claim, and keep an eye out for results from our year-long study!
Sample Storage Temperature Comparisons
Caltech Sustainability -70C/-80C Case Study
Additional links with advice on how to keep your freezer running optimally:
Freezer Best Practices Overview
Improving Freezer Efficiency Is (Ultra) Cool!
9 Ways to Make Your Refrigerator More Efficient
Additional studies and links:
Caltech Freezer Rebate Program (save between $2,000 and $8,500 on a new freezer!)
MIT: Putting the Freeze on Lab Energy Waste
Useful References:
Check out the Lab Spring Clean Event for more information, freezer and inventory signage, freezer defrost guide, and more!
Cold Storage Fact Sheet (simple)
Cold Storage Fact Sheet (detailed)