Germ-free animal

Germ-free animals are animals that have no microorganisms living in or on them. Such animals are raised within germ-free isolators in order to control their exposure to viral, bacterial or parasitic agents.^[1] When known strains of bacteria or microbiota are introduced to a germ-free animal, it usually referred to as a gnotobiotic animal, however technically speaking, germ-free animals are also gnotobiotic because the status of their microbial community is known.^[2]

Germ-free animals are used in the study of probiotic research and other animal research requiring careful control of outside contaminants that can affect the experiment.^[3]

References

1. University of Michigan Germ Free Animal Facility - example facility for raising germ-free animals
2. Reyniers, J.A. Germfree Vertebrates: Present Status (1959) Annals of the New York Academy of Sciences. 78(1):3.
3. Of Probiotics and Possibilities - J. Armbrecht. Dept of Bacteriology, University of Wisconsin-Madison. August 2, 2000.