DMEM (Dulbecco's modified Eagle's medium) is a widely used cell culture media in laboratories. It provides essential nutrients, vitamins, amino acids, and minerals to support the growth and proliferation of various types of mammalian cells. DMEM is often supplemented with fetal bovine serum and antibiotics to create an optimal environment for cell culture studies. Researchers use DMEM to maintain cell viability and functionality during experiments due to its balanced composition that mimics the natural cellular environment.