Basic Services|Germ Free


Germ free defined as free of all foreign life forms (e.g., bacteria, viruses, etc.). Germ free rodents adapt anatomically and physiologically to environment devoid of microflora. They have greater nutritional requirements but grow and breed similar to rodents raised in conventional or specific pathogen free (SPF) conditions. Germ free animals are major means to obtain data about the relationship between host and its microflora including in immunology, neurology, diet and nutrition and more.

The germ-free-facility

The germ-free mouse facility at the Weizmann institute of science is situated at the Lorry Lokey building (MAMTAK). In the facility, mice are housed in semi-rigid isolators (Park Bioservices, LLC) in which they remain free of all bacteria, exogenous viruses, fungi, and parasites.
Any equipment, supplies and experimental substance that enter the isolator must be first sterilized by autoclave, irradiation or gas. Regular monitoring of the germ free status is done by the Institute`s Diagnostic and Quality Assurance Laboratory, using qPCR and standard culturing of fresh feces, water and food.
The germ free facility is sub divided into breeding and experimental units.
The breeding facility currently has numerous breeding isolators to maintain strains. The experimental unit has 2 experimental isolators and 2 racks of isocages (Techniplast). These are used to maintain the germ-free or gnotobiotic (all life forms are known) status of the mice during experiments. Germ free mice that were inoculated with SPF flora can be transferred to other (SPF) facilities (following permission).
For colonization studies, germ-free mice can be inoculated with a suspension of a specific microbe (mono-colonization), a defined group of microbes, or a polymicrobial mixture. These defined microbial populations are regularly established and used in our facility to study microbiome-host interactions.

Current mouse strains:

  • Outbred Swiss Webster (Taconic)
  • C57BL/6J (obtained from Hanover University)
  • Balb/c (obtained from Hanover University)

Other strains or mutants can be rendered germ free by rederivation following request of the PI and IACUC approval. In addition, germ free mice can be imported and exported using a customized germ free shipper.

The professional personnel will be pleased to assist and answer any other questions.

The team: Carmit Bar-Natan, Efrat Aziza, Shay Arazi, Elena Golodnitsky, Amos Yitzak 

Attending veterinarian: Gil Hecht


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