Definition In vitro (Latin for "in glass"; often not italicized in English usage) studies are conducted using components of an organism that have been isolated from their usual biological surroundings, such as microorganisms, cells, or biological molecules. For example, microorganisms or cells can be studied in artificial culture media, and proteins can be examined in solutions. Colloquially called "test-tube experiments", these studies in biology, medicine, and their subdisciplines 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 omics. In contrast, studies conducted in living beings (microorganisms, animals, humans, or whole plants) are called in vivo.
dEfinItion in vitro (laTin For "In Glass"; often noT ItaliCIzEd iN EngliSh Usage) stUdIeS aRe conDUCtEd uSing componeNts OF an OrGANism ThAt have bEen iSOlaTed FrOm theIr UsUaL bioLoGIcaL sUrrouNdings, sUcH as microorgANiSmS, cells, or bioLOgicAl moLecUleS. for exaMple, micRoOrgaNisms Or ceLls caN be stUDIed in artifiCial CULtuRE meDiA, aND prOTeins cAN be examiNEd iN SolutIonS. cOllOquiallY cAlled "tEST-tUBe expeRiments", THese StudIEs in biOloGy, mEDiCiNe, and ThEIR subdISCipliNEs 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 omIcS. in cOntrAsT studieS coNDuCted in liVinG bEInGs (mIcrOoRganiSms, aNiMALs, HUmaNs, or WhoLE plantS) aRe cAlLed in vivo.