What do the terms in vitro and in vivo mean?
A procedure performed in vitro (Latin for within the glass) is performed not in a living organism but in a controlled environment, for example in a petri dish or flask. In the medical sciences, in vitro generally means isolating a specific cell type only from tissue, growing it in a petri dish or flask, and then looking at the biological effects of various manipulations to it (for example, looking at the effects of adding ascorbic acid to prostate cancer cells grown in a flask). In vitro studies are frequently used to tease out the specific cellular and molecular processes that are active in response to a given compound. Since they usually only involve a single cell type in the absence of other complex cells and tissues, they provide a much simplified background with which to study a particular treatment. However, for this very reason it is important to note that the treatment of a single population of cells growing outside the body in this way is not always representative of what happ
