About Us

The National Gnotobiotic Rodent Resource Center (NGRRC) has provided germ-free and selectively colonized mice to requesting investigators since 2002.  In addition, we derive germ-free mouse strains by sterile embryo transfer using a clean air hood and specialized sterile techniques. Germ-free mice are maintained in sterile flexible film Trexler isolators. To study the impact of microbes on host health and disease, mice can be maintained germ-free, selectively inoculated with known bacterial species, or colonized via fecal microbiota transplantation.  Mice can be purchased and shipped to investigators or experiments can be carried out in our facility.  Please link [HERE] for additional information regarding technical services and animal availability, and [HERE] to request animals or services.


Director: R. Balfour Sartor, M.D., Midget Distinguished Professor of Medicine, Microbiology and Immunology, brings over 24 years of internationally recognized experience with genetically engineered gnotobiotic rats and mice. He pioneered studies demonstrating that a subset of commensal luminal bacteria induces chronic, immune-mediated inflammation in genetically susceptible rats and mice and stimulates protective mucosal and systemic immune responses in normal hosts. In addition, he has demonstrated both host and bacterial strain-specific responses in experimental colitis, regulation of host genes by enteric bacterial colonization, and regulation of enteric bacterial genes by the host’s inflammatory response.

Technical Director: Maureen Bower, RLATg, has been Technical Director of the NGRRC since 2002. Her expertise in gnotobiotic technique is well-recognized on national and international levels and qualifies her to train personnel in gnotobiotic protocols.  In addition, she oversees routine facility operations, equipment maintenance, quality control, record keeping, germ-free derivations, scheduling, and staff gnotobiotic technicians.

First time users please contact Sue Tonkonogy, Ph.D., Associate Professor at the College of Veterinary Medicine at North Carolina State University, who brings over 15 years of experience with gnotobiotics. Dr. Tonkonogy will discuss intricacies of working in gnotobiotics and facilitate the planning of your experiment.\

Gnotobiotics Steering Committee:

Janelle Arthur, Ph.D., Assistant Professor of Microbiology & Immunology at UNC-CH

Maureen Bower, B.S., RLATg, Technical Director of Gnotobiotic Core at UNC-CH

Ajay Gulati, M.D., Associate Professor of Pediatrics at UNC-CH

Jonathan Hansen, M.D., Ph.D., Associate Professor of Medicine at UNC-CH

Balfour Sartor, M.D., Midget Distinguished Professor of Medicine at UNC-CH

Sue Tonkonogy, Ph.D., Associate Professor, College of Veterinary Medicine, NCSU


The NGRRC is currently funded by the National Institutes of Health (NIH) Office of the Director, Crohn’s and Colitis Foundation of America (CCFA), and the NIH-funded Center for Gastrointestinal Biology and Disease (CGIBD) at the University of North Carolina Chapel Hill and North Carolina State University.