Northwestern University Feinberg School of Medicine

Center for Genetic Medicine


The process of rederivation eliminates pathogens such as pinworm, parvovirus, and mouse hepatitis virus from infected mouse lines. Pre-implantation embryos, which are relatively resistant to such pathogenic microorganisms due to the physical barrier of the zona pellucida surrounding the embryo, are collected from infected mice and washed through several droplets of embryo culture media, then surgically transferred into specific pathogen-free pseudopregnant females. Resulting mice can then be transferred to the barrier-level vivarium in the Lurie Research Center. Rederivation allows the import of established mouse lines with either known pathogens or of unknown health status from anywhere in the world.

Prior to scheduling rederivation

Note: CCM must initially approve the receipt of all animals into the vivarium

Submit an Animal Import request to CCM and they will:

If opting to have the TTML rederive the line, complete and return the Rederivation Request form and we will:

The rederivation process

Expected results

Your responsibilities following rederivation


Services include:


Costs include the purchase of wild-type mice used for the project; the housing of the surrogate females; and limited housing of weaned pups.

Investigators are responsible for the following costs

Shipping costs: all purchase and shipping costs required to obtain males/ship SPF pups

Housing costs:

Pathogen testing: all costs associated with additionally required testing

For pricing information, click here.