MTT assays are laboratory techniques used to assess cell viability and proliferation. The method involves adding a yellow dye called MTT to cultured cells. Living cells convert MTT into a purple formazan product, which can be quantified by measuring absorbance with a spectrophotometer. This assay is widely used in pharmacology and toxicology to evaluate the effects of drugs or chemicals on cell health. It provides a simple and reliable way to determine how many cells are alive after treatment, helping researchers understand the impact of various substances on cellular functions.