What is the Difference Between In Vitro and In Vivo?

The terms "in vitro" and "in vivo" describe different types of scientific research and experimental methods used in medical and biological studies. Here are the key differences between the two:

• In vitro is Latin for "in glass" and refers to studies performed outside of a living organism, such as in a laboratory dish or test tube. This methodology allows scientists to evaluate various biological phenomena in specific cells and perform more detailed analyses. However, in vitro studies cannot replicate the conditions that occur inside a living organism, which may limit the applicability of the results.
• In vivo is Latin for "within the living" and refers to tests, experiments, and procedures conducted in or on a whole living organism, such as a person, laboratory animal, or plant. In vivo studies provide a more accurate representation of the conditions inside a living organism but may be more complex, time-consuming, and expensive compared to in vitro studies.

Both in vitro and in vivo studies are essential for understanding the pharmacokinetic/pharmacodynamic profile of a drug. They are often used in combination during the drug development process, with in vitro models providing initial insights into a cell's response, followed by in vivo studies to evaluate the drug's safety, efficacy, and delivery in living organisms.

Comparative Table: In Vitro vs In Vivo

Here is a table highlighting the differences between in vitro and in vivo studies:

In vitro studies are conducted outside of living organisms, typically using isolated cells, tissues, or biological molecules in controlled laboratory settings. These experiments allow researchers to manipulate and analyze specific aspects of biological systems with precision. On the other hand, in vivo studies involve living organisms, such as animals or humans, and provide a comprehensive view of biological processes within the intact organism. While in vitro studies offer controlled conditions and higher precision, in vivo studies are better suited for observing overall effects, interactions, and long-term observations. Both in vitro and in vivo studies are not mutually exclusive but rather complementary, each contributing unique insights to the understanding of complex biological phenomena.