Medicine. In an artificial environment outside a living organism or body. For example, some toxicity testing is done on cell cultures or slices of tissue grown in the laboratory, rather than on a living animal [compare within vivo]
Agency for Toxic Substances and Disease Registry, Centers for Disease Control and Prevention, Glossary of Terms, Atlanta, GA, USA 2009. http://www.atsdr.cdc.gov/glossary.html, (Tox - Amer) {788}