It’s all Latin to me!

February 2, 2017

Dr. Kathryn Sobek, Filipodia Editor


The use of Latin terms in scientific writing is common. From abbreviations (i.e., etc., e.g.) to words (versus, circa) to phrases (in vivo, in vitro), the use of Latin words can help clarify your writing. Today, we will be discussing the meaning and correct usage of several common Latin phrases.

In vitro translates to ‘in glass’ and refers to a process performed in a test tube or culture dish. Examples of ‘in vitro’ experiments are cell or tissue culture using immortalized cell lines or experiments on cellular extracts.

Ex vivo translates to ‘out of the living’ and refers to a process performed outside an organism with minimal alteration of the natural conditions. Ex vivo and in vitro do not have the same meaning even though both types of experiments are performed outside the organism. The results from ex vivo experiments can apply to the organism where as results from in vitro experiments can apply to the cell line used. A common ex vivo experiment is the chorioallantoic membrane (CAM) assay.

In vivo translates to ‘in a living thing’ and refers to a process performed in a living organism. We typically refer to in vivo experiments as research performed in mice, rats, dogs, etc., but includes humans in clinical trials and plants as well.

In silico translates to ‘in silicon’ and refers to experiments conducted through computer modeling or simulation. Examples of in silico experiments are cell modeling or drug discovery.

Side note: I learned to italicize these Latin phrases. However, some journals have specific guidelines about which words to put in italics and do not want these phrases italicized. This is just another friendly reminder to always check the style of the journal you are submitting to before you click the submit button!