Storing your biological samples in an ultra-low temperature (ULT) freezer set at -80°C often feels like something of a laboratory custom; often lab personnel will even refer to their ULT freezer simply as the “minus 80”. However, as ingrained as this practice may be, raising your freezer cabinet temperature by just 10°C can lead to significant energy savings which, as every laboratory manager knows, can have a huge impact on both the laboratory’s energy consumption and environmental footprint. Here we explain how storing your samples at -70°C instead can provide you with a more sustainable cold storage option.
It may seem like raising the overall cabinet temperature from -80°C to -70°C is too much of a risk to take, particularly when storing samples that represent hours of hard work, and may form the basis all future research. However, the vast majority of frozen biological material simply does not have to be kept at -80°C. Nucleic acids will remain fully viable when stored at -20°C or -70°C (depending on the intended duration of storage). This is also the case for bacteria, viruses, and even proteins, which can all be stored without issue at -70°C. In fact, laboratories at a number of leading universities have been adopting this new set point for their ULT freezers, and have continued to produce some of the world’s most cutting-edge research. If you know the nature of the samples you’re storing, and for how long they are intended to be kept in cold storage, then there is no reason to suggest that you need to keep them at -80°C.
Reducing your laboratory footprint
A lot of laboratories today are seeking ways in which to reduce energy expenditure. Not only does this reduce the impact that the research may be having on the environment, but also reduces the associated energy costs, which can be especially high for equipment such as freezers that run continuously. While increasing the freezer set point to -70°C can reduce energy usage by up to 30%1, ensuring that your lab is fitted with the most up-to-date equipment is also important. Manufacturers are responding to ever increasing regulations with technological advances being made to ensure that systems operate more efficiently, and are manufactured in a more environmentally friendly manner.
By using this higher temperature set point, your lab will ultimately be responsible for fewer greenhouse gas emissions1, enabling you to operate in a more environmentally-friendly and sustainable manner than before. Due to the number of different sample types that can be stored long-term at -70°C without suffering any detrimental effects, you can be confident that following the lead already taken by a number of universities, government and pharma/biotech companies will not harm your research. These measures will instead help to contribute to the preservation of the environment, and the continuation of sustainable science.
If you’re actively looking at more sustainable storage practices, why not participate in the North American Laboratory Freezer Challenge? Through friendly competition, the challenge aims to promote energy efficiency and sample integrity in laboratories across the nation. Sign-up here: http://www.freezerchallenge.org/sign-up.html