How does in vitro testing compare with in vivo testing?

In vitro testing is a complementary scientific tool that provides clues about which drugs might be effective against your unique form of cancer. This information can be helpful in making decisions about which drugs to test in your mouse avatars, but it is not required to proceed with in vivo pharmacology testing.

In vitro is Latin for in glass. It describes medical procedures, tests, and experiments that researchers perform outside of a living organism. An in vitro study occurs in a controlled environment, such as a test tube or petri dish. In vivo is Latin for within the living. It refers to tests, experiments, and procedures that researchers perform in or on a whole living organism.

In cancer research, in vitro tumor models are often used to examine the characteristics of individual cancer cells. While this method can reduce complexity and cost, it can present significant treatment and prognostic challenges.1

Cancer cells within a tumor are highly heterogeneous (dissimilar) and are unable to replicate the complicated environment and mechanisms of a solid tumor and its growth.2 Dissociated cancer cells are more vulnerable to anticancer agents, which may lead to false positives.

1 Elmore, LW et al. Blueprint for cancer research: Critical gaps and opportunities. CA Cancer J Clin. 2021.
2 Bartlett, R et al. Personalized In Vitro Cancer Modeling — Fantasy or Reality? Transl. Oncology, Vol. 7, Issue 6, 20214, pg.657-664, ISSN 1936-5233.