Cell viability refers to the ability of cells to survive and function properly. It is an important measure in biology and medicine, as it helps researchers understand how cells respond to various treatments, such as drugs or environmental changes. Viable cells can grow, divide, and perform their normal functions, while non-viable cells are dead or unable to carry out these processes. To assess cell viability, scientists often use techniques like trypan blue exclusion or MTT assays. These methods allow them to distinguish between live and dead cells, providing valuable information about the health of a cell population. Monitoring cell viability is crucial in fields like pharmacology and toxicology.