What does vitro mean?
Vitro is encountered in English chiefly within the scientific phrase “in vitro,” a Latin expression meaning “in glass.” It describes biological work performed outside a living organism, such as testing a drug on cultured cells, growing microorganisms in laboratory dishes, or examining tissue under controlled conditions. The distinction is important in scientific literature: an in vitro study isolates particular cells, molecules, or other biological materials, whereas a study conducted within a living organism is described as in vivo. Results obtained in vitro can be rapid and precisely controlled, although they may not always predict what happens in a complete organism. The phrase became established in English scientific usage during the 19th century and is now used across scientific disciplines worldwide. Although its literal reference to laboratory glassware is no longer always exact, vitro remains the standard way to identify experimental conditions that take place outside a living organism.
adverbChiefly in the phrase “in vitro,” meaning “in glass” and referring to a biological process, experiment, or culture conducted outside a living organism, typically in laboratory glassware or controlled culture conditions.
- In the phrase “in vitro,” outside a living organism, especially in laboratory glassware or controlled culture conditions.
"The compound was tested in vitro before the researchers began animal studies."
"The drug was tested in vitro before the researchers began animal studies."
"Scientists used in vitro culture to examine how the plant cells respond to drought."
Vitro comes from Latin for “in glass”: a tiny phrase for science conducted outside a living organism.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of vitro
The phrase comes from Latin in vitro, literally “in glass,” with vitro being the ablative singular of vitrum, meaning “glass.” It entered English scientific usage during the 19th century to describe biological work performed outside a living organism. English words such as vitreous and vitrify continue to reflect the same Latin root.
How vitro is actually used
Vitro is almost always used within the established phrase “in vitro” and is not normally used as a standalone ordinary English word. The expression is formal and technical, particularly common in biology, medicine, pharmacology, and related sciences.