The Mutant Mouse Resource and Research Center (MMRRC), the official National Institute of Health (NIH) repository of mouse models, is pleased to announce the availability of genetically-altered mice and embryonic stem (ES) cells made as part of the NIH Knockout Mouse Project (KOMP) and previously maintained in the KOMP Repository. The KOMP Repository collection will provide investigators with the convenience of a one-stop portal to one of the largest inventories of mutant mouse strains and ES cell lines available to the biomedical research community.

These newly acquired mouse and ES cell lines have been deposited into the MMRRC at UC Davis. The MMRRC at UC Davis is the largest of four regional archive and distribution centers in the NIH consortium. The MMRRC functions as a single repository resource and is comprised of an Informatics, Coordination and Service Center (ICSC) and three additional regional distribution facilities which include: The Jackson Laboratory, University of Missouri, and University of North Carolina, Chapel Hill. The newly available KOMP Repository mice (4,175 unique lines) & ES cell lines (14,013 unique mutant lines and 7 parental lines) can be accessed by visiting the MMRRC website ( and typing in "KOMP Repository" in the search function, or by using the advanced search function and indicating “Major Collection = KOMP", and then searching by gene of interest, which will allow filtering for ES cells or mice.

The MMRRC was created in 1999, and is supported through the NIH, Office of Infrastructure and Research Programs (ORIP), as the nation’s premier mouse archive and distribution repository. Since that time, the MMRRC has earned an international reputation for the management, cryopreservation, and distribution of scientifically valuable, genetically engineered mouse strains and mouse ES cells. In partnership with researchers around the globe, the MMRRC continues to expand its holdings of mouse models. Today, with more than 59,000 available models, the MMRRC serves as a valuable resource to drive research discoveries for human disease.

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Welcome to the Mutant Mouse Resource & Research Centers (MMRRC) Website

The MMRRC is the nation’s premier national public repository system for mutant mice. Funded by the NIH continuously since 1999, the MMRRC archives and distributes scientifically valuable spontaneous and induced mutant mouse strains and ES cell lines for use by the biomedical research community. The MMRRC consists of a national network of breeding and distribution repositories and an Informatics Coordination and Service Center located at 4 major academic centers across the nation. The MMRRC is committed to upholding the highest standards of experimental design and quality control to optimize the reproducibility of research studies using mutant mice. The MMRRC is supported by the Office of Research Infrastructure Programs (ORIP) in the Office of the Director at NIH. More than 50,000 mutant alleles are maintained as live mice, cryopreserved germplasm, and/or mutant ES cells. Live mice are supplied from a production colony, from a colony recovered from cryopreservation, or via micro-injection of ES cells. An MMRRC facility may offer cryopreserved material for resuscitation at the recipient scientist's institution.