Rederivation of mouse strains
Rederivation from cryopreserved/thawed embryos
Many mouse strains/lines are cryopreserved as embryos to preserve the line without maintenance breeding, to serve as a backup against a potential pathogen outbreak and to transfer strains between facilities/institutions.
When lines need to be rederived from cryopreserved stocks, embryos are thawed, cultured and then transferred in to pseudopregnant females.
Read more about rederivation from cryopreserved/thawed embryos.
Rederivation from live mice/fresh embryos
The rederivation of mouse lines through embryo transfer is used to establish Specific Pathogen Free (SPF) mice from mice of any compromised health status. Pre-implantation embryos are produced via IVF then transferred into pseudopregnant females in an SPF facility.