- Cryopreserved cells can be stored in either liquid or vapor phase nitrogen, and choosing between these methods requires careful consideration of several factors. The liquid phase storage method maintains cells at a constant -196°C by direct immersion in liquid nitrogen. This approach is particularly beneficial for temperature-sensitive cells such as embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), neuronal cells, immune cells, and gametes. While liquid phase storage requires more rigorous safety protocols and carries a risk of vial explosion during thawing due to nitrogen seepage, it remains advantageous when long-term storage stability is crucial and monitoring resources are limited.
- Vapor phase storage, which keeps cells at temperatures ranging from -150°C to -190°C, offers distinct advantages for certain applications. This method significantly reduces the risk of cross-contamination between samples and minimizes the danger of vial explosion during thawing since samples aren’t in direct contact with liquid nitrogen. It’s particularly suitable for frequently accessed samples and those with potential contamination concerns, such as primary cultures or cells with known microbial presence. However, vapor phase storage requires more frequent nitrogen replenishment and closer monitoring due to temperature fluctuations.
- The decision between these storage methods should be based on specific laboratory needs, considering factors such as cell type sensitivity, access frequency, contamination risks, available monitoring systems, staff resources, and nitrogen supply reliability. Each facility must weigh these factors carefully to determine the most appropriate storage method for their particular circumstances. Regular maintenance, proper safety protocols, and careful documentation are essential regardless of the chosen storage method to ensure sample viability and laboratory safety.
