 studies that are in vitro (; often not italicized in english) are performed with cells or biological molecules studied outside their normal biological context; for example proteins are examined in solution, or cells in artificial culture medium. colloquially called "test tube experiments", these studies in biology and its sub-disciplines are traditionally done in test-tubes, flasks, petri dishes etc. they now involve the full range of techniques used in molecular biology such as the so-called omics. studies that are conducted using components of an organism that have been isolated from their usual biological surroundings permit a more detailed or more convenient analysis than can be done with whole organisms. in contrast, in vivo studies are those conducted in animals including humans, and whole plants. examples of in vitro studies include: the isolation, growth and identification of microorganisms; cells derived from multicellular organisms (cell culture or tissue culture); subcellular components (e.g. mitochondria or ribosomes); cellular or subcellular extracts (e.g. wheat germ or reticulocyte extracts); purified molecules (often proteins, dna, or rna, either individually or in combination); and the commercial production of antibiotics and other pharmaceutical products. viruses, which only replicate in living cells, are studied in the laboratory in cell or tissue culture, and many animal virologists refer to such work as being in vitro to distinguish it from in vivo work on whole animals. == advantages == living organisms are extremely complex functional systems that are made up of, at a minimum, many tens of thousands of genes, protein molecules, rna molecules, small organic compounds, inorganic ions and complexes in an environment that is spatially organized by membranes and, in the case of multicellular organisms, organ systems.{{cite book |author=alberts, bruce |title=molecular biology of the cell |publisher=garland science |location=new york |year=2008 |pages=
Alternatives_to_animal_testing Animal_test_conditions Latin_biological_phrases