It is not desired or even possible to keep all the mouse lines live in animal houses, therefore, cryopreservation of embryos and in vitro fertilization methods have been developed to preserve scientifically valuable mutant mouse strains in the form of frozen germ cells and embryos. To make these resources available to the entire biomedical research community, central mouse repositories, operating with standardized procedures and highest‐quality standards, have been established.
European Mouse Mutant Archive (EMMA) is a non‐profit repository for the collection, archiving (via cryopreservation) and distribution of relevant mutant strains essential for basic biomedical research. The TG core facility of Biocenter Oulu is currently being established to serve as the Finnish EMMA node.
The International Mouse Strain Resource, IMSR is a searchable online database of mouse strains and stocks available worldwide.