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n. (used with a sing. verb)
The study of organisms or environmental conditions that have been rendered free of bacteria or contaminants or into which a known microorganism or contaminant has been introduced for research purposes.

[Greek gnōtos, known; see gnō- in Indo-European roots + biotics, study of living organisms.]

gno′to·bi·ot′ic adj.


(Biology) (functioning as singular) the study of organisms living in germ-free conditions or when inoculated with known microorganisms
[C20: from Greek, from gnōtos, from gignōskein to know + bios known life]
ˌgnotobiˈotic adj
ˌgnotobiˈotically adv


a branch of biology that studies animals under germ-free conditions.
See also: Biology
References in periodicals archive ?
We will use this unique system, coupled with innovative robotic high-throughput modalities, gnotobiotics, metagenomics and multiple genetically altered mouse models to generalize our studies and decipher the critical principles governing host-microbiome interactions.
1957 A new field called gnotobiotics, "the study of animals in a germ-free or germ-controlled environment," is described (1/26/57, p.