Cryopreservation is the process of freezing germplasm for stable, long-term storage in liquid nitrogen. It is a safe method for preserving viable pre-implantation embryos or sperm that can be easily recovered at a future date to revive the line. It is a mainstream technique used by all major mouse vendors and international repositories (e.g., IKMC, MMRRC, KOMP2 and RIKEN) and most major research institutions. It provides a means for NU investigators to bank valuable, well-characterized mouse lines that are no longer routinely used, freeing up animal space and resources, both in time spent maintaining colonies and animal housing costs.
There are many reasons to consider cryopreservation of your mouse lines:
- Cryopreservation insures against loss of colonies in the event of a natural catastrophe. For example, liquid nitrogen dewars used to store frozen embryos have withstood both fires and floods at various institutions faced with such disasters.
- Cryopreserved stocks can easily and quickly be thawed in the event of an infectious outbreak or reproductive failure within a colony.
- Economically, cryopreservation results in significant long-term cost savings and mouse room space. Valuable, well-characterized mouse lines that are no longer routinely used can be safely stored as frozen embryos.
- Cryopreservation of stock lines helps to control genetic drift and serves as a genetic resource for refreshing mouse lines.
- Cryopreservation is recommended for transgenic lines susceptible to transgene instability.
- Cryopreserved stocks can be shipped to or from collaborators worldwide.