Cryopreservation (cryogenic preservation) is “the storage of cells, tissues and organs following appropriate ‘preparatory’ procedures at the ultra-low temperature of liquid nitrogen (–196°C).” (1) This form of preservation is ideal for biobanking because these cold temperatures slow chemical and physical reactions of the biomolecules and biospecimens and stop the samples from degrading.
Liquid nitrogen biobanks are ideal because they require low electricity usage, resulting in significant savings in operating costs. However, using liquid nitrogen biobanks requires careful planning and maintenance to ensure safe conditions for workers handling the samples and a suitable environment for the samples themselves. (1) The most important safety concern is the escape of nitrogen from the refrigerators – liquid nitrogen vaporizes in the atmosphere, which poses an asphyxiation risk. Low oxygen alarms can mitigate this risk, as well as regular preventative maintenance.
When preparing a liquid nitrogen biobank, it’s important to consider the volumes being stored in order to help determine the size of the liquid nitrogen tank. For example, some tanks have enough capacity 10,000 2 ml vials, and others have enough for 35,000 vials. Proper implementation of instruments includes the connection to remote alarms to allow intervention in case of any emergencies. Ideally, these biobanks should have a local alarm, a remote alarm under constant surveillance and an automatic dialer that can alert managers in charge of the system. (2)
While liquid nitrogen biobanks are becoming more common for their ability to store samples long-term, there are several considerations to keep in mind. These types of biobanks can offer cost savings, but they require workers to be educated about the safety risks and conditions, as well as how to maintain the samlpes in suitable environments. Careful planning is advised!
1. Mercuri, A., Turchi, S., Borghini, A., Chiesa, M., Lazzerini, G., Musacchio, L. and Adreassi, M. (2013) Nitrogen biobank for cardiovascular research. Curr. Cardiol. Rev. 9, 253.
2. Barbareschi, M., Cotrupi, S. and Guarrera, G. (2008) Biobanks: instrumentation, personnel and cost analysis. Pathologica 100, 144.