Medium 199, with L-glutamine, is widely used in cell culture applications, particularly for the growth and maintenance of a variety of cell types. It is commonly employed in research laboratories for culturing primary cells, including fibroblasts, epithelial cells, and endothelial cells. The medium provides essential nutrients, vitamins, and amino acids, with L-glutamine serving as a critical energy source for cell metabolism. It is also utilized in virology studies for the propagation of viruses and in vaccine production. Additionally, Medium 199 is often used in tissue engineering and regenerative medicine to support the growth of cells in three-dimensional cultures. Its balanced composition makes it suitable for both short-term and long-term cell culture experiments.