In vitro research refers to studies conducted outside of a living organism, typically in a controlled environment such as a test tube or petri dish. This type of research allows scientists to investigate biological processes, test the efficacy of drugs or treatments, and study the effects of various factors on cells or tissues in a controlled setting. In vitro research is often used as a preliminary step before moving on to in vivo studies in live animals or clinical trials in humans. It is a valuable tool for advancing our understanding of diseases, developing new therapies, and testing the safety and effectiveness of medical interventions.