in the year of our Lord
about; used especially in approximate dates
and others; and elsewhere
and the rest; and so forth; and so on
for example; such as
in the aformentioned place
in the work cited
quod erat demonstrandum
which had to be shown
that is to say; namely
Ex vivo (Latin: out of the living) means that which takes place outside an organism. In science, ex vivo refers to experimentation done in or on living tissue in an artificial environment outside the organism. The most common "ex vivo" procedures involve living cells or tissues taken from an organism and cultured in a laboratory apparatus, usually under sterile conditions for a few days or weeks. This allows experimentation under highly controlled conditions impossible in the intact organism, albeit at the expense of looking at the tissue in its "natural" environment. One widely performed ex vivo study is the chick chorioallantoic membrane (CAM) assay. In this assay, angiogenesis is promoted on the CAM membrane of a chick embryo outside the organism (chicken). Ex vivo studies are usually performed in vitro, although the use of these two terms is not synonymous.
In vivo (Latin: within the living) means that which takes place inside an organism. In science, in vivo refers to experimentation done in or on the living tissue of a whole, living organism as opposed to a partial or dead one or a controlled environment. Animal testing and clinical trials are forms of in vivo research.
In vitro (Latin: within the glass) refers to the technique of performing a given experiment in a controlled environment outside of a living organism; for example in a test tube. In vitro fertilization is a well-known example of this. Many experiments in cellular biology are conducted outside of organisms or cells; because the test conditions may not correspond to the conditions inside of the organism, this may lead to results that do not correspond to the situation that arises in a living organism. Consequently, such experimental results are often annotated with in vitro, in contradistinction with in vivo .
In silico is an expression used to mean "performed on computer or via computer simulation." The phrase is coined from the Latin phrases in vivo and in vitro that are commonly used in biology (see also systems biology) and refer to experiments done in living organisms and outside of living organisms, respectively. Contrary to widespread belief, in silico does not mean anything in Latin.