Cell-based assays are laboratory techniques that use living cells to study biological processes and test the effects of various substances, such as drugs or chemicals. These assays help researchers understand how cells respond to different conditions, which is crucial for drug development and disease research. By observing changes in cell behavior, such as growth, death, or signaling pathways, scientists can gather valuable data. Common types of cell-based assays include cytotoxicity assays, reporter gene assays, and cell proliferation assays. These methods are essential for evaluating the safety and efficacy of new treatments before they are tested in humans.