in vivo
Meaning of in vivo: In vivo describes a process or experiment studied within a living organism, contrasted with laboratory based methods that use isolated cells or tissue.
Definition of in vivo
In vivo describes something that occurs or is studied within a living organism, as opposed to being observed outside a living body, such as in a laboratory dish or test tube. The term is used across biology and medicine whenever it matters whether a process was observed in an intact living system.
Research findings from in vivo studies, which are conducted in whole animals or, in some cases, in human participants, are generally considered to reflect biological processes more completely than findings from in vitro studies, since a living organism includes interacting systems, such as circulation and immune response, that are absent from an isolated sample.
A related term, ex vivo, describes tissue or cells taken from a living organism and studied outside the body, occupying a middle position between fully in vivo and fully in vitro research, since the material originated from a living source even though it is examined outside it.
Used in a sentence
The drug showed promising activity in vitro, and further testing in vivo was planned.
Good to know
In vivo findings are generally considered more representative of actual biological behavior than in vitro findings, since an intact living organism includes interacting systems that an isolated laboratory sample does not.
Word origin
Where “in vivo” comes from
Formed from Latin in, meaning in, and vivo, from vivus, meaning alive or living.