In Vivo

In vivo is a Latin phrase that literally translates to “within the living.” It is a type of experiment that uses the whole living organism instead of just a part of a body or a cadaver. In vivo is the direct opposite of an in vitro procedure (Latin for “within the glass,” more commonly used to refer to experiments done in a petri dish or a test tube). Two of the most common forms of in vivo research are clinical trials and animal testing. Many scientists prefer in vivo testing over in vitro procedures because the overall effect of a specific experiment is easily observable on a living subject. In the field of microbiology, in vivo is more commonly used to refer to the experiments performed on live isolated cells instead of the whole organism. An in vivo procedure typically uses cultured cells culled from biopsies. However, this practice is more specifically known as an ex vivo (Latin for “out of the living) procedure. Ex vivo is an experiment or measurement done “in or on a tissue in an artificial environment outside the organism with the minimum alteration of natural conditions.” Scientists can experiment under more controlled conditions compared to in vivo experiments—however, the natural environment can be altered. Ex vivo experiments are more preferable than in vivo ones because scientists will be able to perform measurements and tests that will not be ethically possible in living subjects. Tissues for an ex vivo test can be removed through a wide variety of ways, including by part, by removing the whole organs, or removing larger organ systems. Ex vivo specimen uses include assays, realistic models for the development of surgical procedures, investigating the interactions of different energy types with an organism’s tissues, and measuring tissue properties in different kinds of extreme environments. This category contains scientific information about the processes of in vivo and ex vivo, which are experimentation procedures that use organisms which are organizations of living cells.