Housing Gnotobiotic Mice in Conventional Animal Facilities

Gnotobiotic mice are an established, robust model utilized in current research to study host-microbiota interactions. For years isolators have been used to rear germ-free and gnotobiotic mice. However, isolators can be costly and the segregation of treatments within the same isolator is problematic. Recently, methodologies for housing germ-free mice in specially designed individually ventilated cages (IVCs) operated under barrier mode have been developed; however, this equipment is costly and its operation in barrier mode for research involving germ-free mice and pathogens is not permissible under modern biosafety and biosecurity regulations. This article describes a method to house germ-free mice in a commonly available conventional IVC system operated under containment mode. This technique allows researchers to maintain the germ-free or gnotobiotic status of mice tested up to 4 weeks with weekly handling while working with pathogens using each IVC as a separate experimental unit.