Axenic


Axenic

In biology, axenic describes a culture of a particular organism that is entirely free of all other "contaminating" organisms. The earliest axenic cultures were of bacteria or unicellular eukaryotes, but axenic cultures of many multicellular organisms are also possible. [Citation
last1 = Thain| first1 = M.
last2 = Hickman | first2 = M.
title = Dictionary of Biology (9th edition)
publisher = Penguin Books, London, UK
year = 1994
isbn = 0-14-051288-8
] Axenic cultures are useful because all of the organisms present within them are identical or share the same gene pool. Consequently they will generally respond in a more uniform and reproducible fashion, simplifying the interpretation of experiments.

Axenic cultures of microorganisms are typically prepared using a dilution series of an existing mixed culture. This culture is successively diluted to the point where subsamples of it contain only a few individual organisms, ideally only a single individual (in the case of an asexual species). These subcultures are allowed to grow until the identity of their constituent organisms can be ascertained. Selection of only those cultures consisting of the desired type of organism produces the axenic culture. Subcultures that originate from a single organism or cell without genetic change are considered clones.

Axenic cultures are usually checked routinely to ensure that they remain axenic. One standard approach with microorganisms is to spread a sample of the culture onto an agar plate, and to incubate this for a fixed period of time. The agar should be an enriched medium that will support the growth of common "contaminating" organisms. Such "contaminating" organisms will grow on the plate during this period, identifying cultures that are no longer axenic.

References


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • axenic — adj. 1. raised under sterile conditions; of experimental animals; as, axenic conditions. [WordNet 1.5] 2. pure or completely free of the presence of other organisms; used of cultures of microorganisms; as, an axenic culture. Syn: uncontaminated;… …   The Collaborative International Dictionary of English

  • axenic — [ā zē′nik, āzen′ik] adj. [< A 2 + XEN(O) + IC] not contaminated; gnotobiotic: said esp. of a culture medium devoid of all living organisms except those of a single species …   English World dictionary

  • axenic — A situation in which only one species is present. Thus an axenic culture is uncontaminated by organisms of other species, an axenic organism does not have commensal organisms in the gut etc. Some organisms have obligate symbionts and cannot be… …   Dictionary of molecular biology

  • axenic — adjective a) Containing only a single species of microorganism. For example, an axenic culture means that a pure sample of the organism in question has been grown. This species has resisted all attempts at axenic culture. b) Isolated from… …   Wiktionary

  • axenic — adjective 1. (of experimental animals) raised under sterile conditions axenic conditions germfree animals • Similar to: ↑germfree 2. (used of cultures of microorganisms) completely free from other organisms an axenic culture • Similar to: ↑ …   Useful english dictionary

  • axenic — Sterile, denoting especially a pure culture. Also used to denote “germ free” animals born and raised in a sterile environment. SEE ALSO: gnotobiote. [G. a priv. + xenos, foreign] * * * axe·nic ( )ā zen ik, zēn adj free from other living organisms …   Medical dictionary

  • axenic — sterilumas statusas T sritis ekologija ir aplinkotyra apibrėžtis Gyvųjų mikroorganizmų arba jų sporų nebuvimas kurioje nors aplinkoje, organizme, medžiagoje. atitikmenys: angl. axenic; sterile; sterility vok. Sterilität, f; Unfruchtbarkeit, f rus …   Ekologijos terminų aiškinamasis žodynas

  • axenic — sterilumas statusas T sritis ekologija ir aplinkotyra apibrėžtis Lytiškai subrendusio individo nesugebėjimas lytiškai daugintis (žmogaus ir gyvūnų sterilumas dažniausiai vadinamas nevaisingumu). atitikmenys: angl. axenic; sterile; sterility vok.… …   Ekologijos terminų aiškinamasis žodynas

  • axenic — sterilumas statusas T sritis ekologija ir aplinkotyra apibrėžtis Maisto produktų konservavimas, kai kaitinant, švitinant ultravioletine, gama spinduliuote ar kt. stabdomi biologiniai procesai produktų ląstelėse, sunaikinami mikroorganizmai ir jų… …   Ekologijos terminų aiškinamasis žodynas

  • axenic — adjective Etymology: 2a + Greek xenos strange Date: 1942 free from other living organisms • axenically adverb …   New Collegiate Dictionary


We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.