Cryopreservation (the freezing of mouse sperm and embryos) is used to preserve mouse lines that are no longer needed for research. The technique is also valuable in providing a backup for unique or vulnerable genetically modified lines.

Embryos and sperm are placed in protective media, then frozen and placed in liquid or vapour phase nitrogen vessels for storage at temperatures of
-196°C.  Storage at two separate locations provides additional security. Reproductive materials stored in this manner remain viable indefinitely.

Frozen embryos can be thawed as required and surgically implanted into recipient mothers to produce live pups. When frozen sperm is thawed, in vitro fertilisation (IVF) is used to produce embryos for implantation.

Sperm freezing requires fewer mice and is quicker than embryo freezing. Embryo freezing is preferred for homozygous lines or lines on a mixed background.

The cost of these services can be found in the Downloads section.