Definition:
In vivo refers to a medical test, experiment or procedure that is done on a living organism, such as a laboratory animal or human.
A study done in vivo looks at how the body responds to a particular substance, in contrast to in vitro studies that are done in a test tube or laboratory dish.
Examples:
New chemotherapy drugs for lung cancer are usually studied in vitro, before they are studied in vivo in clinical trials on humans.
