Leibovitz L-15 Medium was originally developed for use in carbon dioxide (CO2) free systems without Sodium Bicarbonate buffer. This medium is buffered by its complement of salts, free base amino acids and galactose substituted for glucose to help maintain physiological pH control. When properly supplemented, Leibovitz L-15 Medium supports established cell lines, such as HEp-2, L929, MRC-5, and LLC-MK2, as well as primary explants of embryonic and adult human tissue. Many viruses have also been successfully cultivated in this medium. This medium exists with or without L-Glutamine.