Skip to main content
U.S. flag

An official website of the United States government

Aged Rodent Colonies

Graphic banner

The Biological Resources Branch within the National Institute on Aging's Division of Aging Biology maintains colonies of barrier-raised, Specific Pathogen-Free (SPF) male and female mice and rats under contractual arrangement with Charles River Laboratories. These animals are for research that is explicitly on aging and are not a source of adult animals for other areas of research. Limited numbers of animals from the NIA aged rodent colonies are available to investigators with active grants at academic and non-profit research institutions under the terms described on the Eligibility Criteria page. They are available free of charge (including shipping) and must be ordered through the Rodent Ordering System (see Ordering Instructions, Shipment of Animals, and Replacement Policy for more information).

For questions about eligibility or ordering animals, or for general inquiries about this resource, please see the Contact Information page.

Important Notices

Notice: P. carinii detected in Barrier R17 of NIA aged rat colony

On August 8, 2022, NIA’s third-party health monitoring service alerted NIA to the detection of Pneumocystis carinii in one rat from Charles River Laboratories (CRL) barrier room R17 that had been submitted for testing on July 13, 2022. On August 22, 2022, CRL confirmed the presence of P. carinii in this barrier room through serological, PCR and histopathology findings. Although CRL does not categorize P. carinii as an excluded agent requiring closure of the colony, it was decided to cease shipping animals from R17 and to eliminate the R17 segment of the colony.

As detailed in this Technical Sheet (PDF, 61.3K), P. carinii infection in immunocompetent rats is a common cause of transient interstitial pneumonia characterized by thickened alveolar septa, lymphohistiocytic infiltrates and perivascular cuffing. P. carinii is a common infection in research rat colonies, with prevalence rate estimated at approximately 6%, making it one of the most common infectious agents reported in research rats. Pneumocystis screening can be performed by both serology and PCR of lung tissue. CRL showed greater success with serology using IFA versus MFIA for animals from R17 and consequently IFA is the recommended serologic assay.

NIA and CRL are taking all necessary steps to identify the source of this contamination and ensure that this unprecedented event does not happen again. The precise duration of the contamination in R17 is not known, but because health monitoring for each barrier room housing the NIA aged rodent colonies is conducted on a monthly basis by CRL and a third-party health monitoring service, we estimate the window for entry of P. carinii into the barrier room after June 15, 2022. Investigators that received rats from R17 after June 15, 2022 have been contacted directly.

R17 is the only barrier affected. Two additional production colonies (K81 in Kingston, NY and R05 in Raleigh, NC) are still available to provide aged rats and it is not anticipated that elimination of R17 will interrupt availability.

Notice: MALE BALB/c

As of July 1, 2023, limited numbers of male BALB/c mice are available for distribution.

An official website of the National Institutes of Health