Research and Funding

Aged Rodent Colonies Handbook

Aged Rodent Colonies Handbook

The National Institute on Aging (NIA), part of the National Institutes of Health (NIH), maintains colonies of barrier-raised, Specific Pathogen-Free (SPF) rodents under contractual arrangement with commercial vendors, specifically for use in aging research. They are not available for use as a general source of adult animals for unrelated areas of research. Animals from the NIA aged rodent colonies are available to investigators at academic and non-profit research institutions under the terms described on the Eligibility Criteria page (link below). NIA rodents are provided through contracts with different contractors and information on the source of specific strains is provided on the Location of Colonies page.

Important Notices:

Eligibility Criteria revised in 2014

Change in F344 Foundation Stock


The NIA has long provided biological resources to the research community to facilitate research on the biology of aging. As of January 1, 2014, the NIA will no longer charge users for the biological resources, nor any related shipping fees due to a new interpretation of the regulations that govern contracting. The NIA is committed to continuing to provide these unique resources to the research community, but this change has significantly increased the cost to the NIA to provide the biological resources, particularly the aged rodent colonies.

As a result of the Budget recently passed by Congress, which restores a portion of the funding cuts made during the Sequester, the NIA is now positioned in fiscal 2014 to maintain its investment in the aged rodent colonies at a level sufficient to meet the demands of the broader aging research community, including grantees funded by the NIH, U. S. government agencies outside the NIH, and U. S. private foundations funding aging research. However, more stringent limitations on use of the aged rodent colonies are required to ensure the continued availability of the animals within the new fiscal environment.

Please review NIA’s new eligibility criteria and restrictions on number of animals per month per grant. While there is a mechanism to apply for an exception to the resource limit, only a very limited number of such requests will be granted, based on scientific need and availability. NIA asks that the research community continue to exercise care and restraint when requesting animals from the NIA aged rodent colonies because even a small increase in the number of animals per order will quickly decimate the animal colonies. Questions about eligibility should be sent to the NIA resources order desk.

Change in source of F344 Foundation Stock

For all previous new F344 colony development, the NIA used foundation stock from the NIH Animal Genetic Resource. This facility was closed around 2004. Unfortunately, the F344 breeding stock from the NIH colony that was sent to the Rat Resource and Research Center would not breed, so this source of F344 stock is lost to us. The last stock we received from the NIH, for the caloric restriction colony, also bred poorly, suggesting an unknown genetic change in the NIH foundation stock. To ensure that we used foundation stock from a source that would likely be available for the long-term and for which the breeding patterns were consistent with F344’s history, we chose the Charles River-derived Fisher rat, F344-cdf. The description of the F344-cdf can be found online.

Before making this decision, we had a genetic comparison done between the F344-nih (n = 18) and F344-cdf (n = 12). On a panel of 106 SNPs spanning all chromosomes, 100 of them were identical between the two colonies (94.3% identity):

  • four markers were fixed for a different allele in F344-cdf from that in F344-nih (chr 1 cM 89.1, chr 2 cM 72.8, chr 4 cM 98.9, chr 10 cM 77.2)
  • one marker was fixed in F344-cdf and segregating in F344-nih (chr 12 cM 27.2)
  • one marker failed in all F344-cdf but worked in all F344-nih (chr 15 cM24.5), suggesting a mutation in the primer region or possibly a deletion in the region

While we cannot be sure how the change in the foundation stock will affect aging phenotypes, we feel that this is the best long-term solution to the loss of the NIH foundation stock. We developed colonies of F344-nih (using breeding stock from our caloric restricted colony started in 2004) and F344-cdf in parallel so that investigators could compare the two substrains in their assays. As of December 2015, all F344 are of the F344-cdf background. 

Cohorts of 150 male and 150 female F344-cdf were set-aside in two barriers for a lifespan study.  The median lifespans were 1-2 months less than for F344-nih as reported in Turturro et al. 1999*.

Percent Survival Male F344-cdf Male F344-nih* Female F344-cdf Female F344-nih*
19 mo.
21 mo.
21 mo.
23 mo.
22 mo.
24 mo.
25 mo.
26 mo.
25 mo.
26 mo.
29 mo.
29 mo.