Germ-Free Mice: Models, Products, and Services
Germ-free mice are essential to microbiome research and the production of specific pathogen-free (SPF) rodent models. Research into the role of microbiota in health and disease has increased during the past decade due to the development of genetically engineered mutant animal models.
C57BL/6-germ-free mouse models may be used as embryo transfer recipients or foster dams for germ-free rederivation of mutant mouse models. In addition, these models may be compared to SPF or Elite (opportunistic pathogen-free) B6N mice to generally assess the relationship between microbiota and phenotypes.
We make it easy for you to assess the biodiversity of bacterial composition of your animal colony and research experiment.
Germ-Free Mouse Colony Health Screening
Our C57BL/6 germ-free colonies are monitored for extraneous bacteria, fungi, and other pathogens. Our microbial cultures can confirm the absence of bacteria in samples from germ-free mice.
If bacterial growth is detected, we work to identify the bacteria and assist in preventing the same agent form showing up in the future. Aerobic and anaerobic cultures of samples obtained from an isolator environment, individual cages, and directly from colony animals are comprehensive, accurate, and sensitive enough to detect infectious agents.
Our health monitoring experts are available to provide guidance on establishing a germ-free assessment program specific to your colony and research, and custom test panels can be developed to suit your specific needs.
Germ-Free Isolator Housing
Special environmental housing conditions help to support animal research with immunocompromised and C57BL/6 germ-free models as well as gnotobiotic, microbiome, and microbial studies. Isolators are used for house and production of immunodeficient, germ-free, transgenic, axenic, and defined flora rodents and gnotobiotic animals.
Our engineering department develops isolators and devises customer-specific solutions when needed. Each product addresses personal safety, and animal welfare.
Frequently Asked Questions (FAQs) About Germ-Free Mice
What are germ-free mice?
Referred to as axenic, germ-free mice have no living microorganisms in or on them. C57BL/6 germ-free mice are bred and raised in isolators to eliminate exposure to viral, bacterial or parasitic agents.
How are mouse models monitored in isolators?
Germ-free colonies are monitored for extraneous bacteria, fungi, and pathogens. A slurry from each isolator consisting of feces and environmental swabs in animal drinking water is inoculated weekly onto various culture media and then incubated.
Wet mounts of the slurries are examined each week by phase microscopy for motile organisms. Feces is collected quarterly from mice in each isolator and is assayed by PCR for the bacterial 16S ribosomal RNA (rRNA) gene. Comprehensive health monitoring for pathogens is performed annually on germ-free mice from each isolator.
What is the difference between germ-free and SPF (specific-pathogen-free) mice?
Mice that are specific-pathogen free (SPF) mice are free of a specific list of disease-causing pathogens by routine testing. The pathogen list can vary from one mouse room to the next depending on barrier levels. Germ-free mice are free of all microorganisms and must be maintained in germ-free isolators to maintain their anxenic health status.
How are germ-free mouse models shipped?
To preserve their germ-free status during shipment, C57BL/6 germ-free mice are transferred from the isolator in which they are housed through the disinfected double-door lock system into cages within a germ-free shipper sterilized with ethylene oxide gas. Upon receipt, the shipper should be attached to the port of the isolator and the mice antiseptically transferred.
What further resources and publications exist for germ-free mice?
Various publications cite germ free mice for a wide range of applications, including: