In Vivo Vs In Vitro: What Do They Actually Mean?

If you’ve spent time reading medical research articles, you’re bound to have seen two Latin phrases that sound a bit like a magical spell: in vivo and in vitro . But what do they actually mean? These phrases aren’t just there to make experiments sound fancier; they reveal where and how the science is being done. The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.

The translations for these are “within the living” ( in vivo ), which involves testing in a living organism, e.g. a mouse, and the other, “in glass” ( in vitro ), involves testing in the lab, such as using cells and tissues. Deciding on which one to use is determined by the type of research. Here’s why these two Latin phrases are at the core of modern biology.

In vit