L-15 Medium (Leibovitz) is formulated for use in carbon dioxide (CO2) free systems requiring sodium bicarbonate supplements. It supports established cell lines, such as human larynx epidermoid cells (HEp-2) and Rhesus monkey kidney epithelial cells (LLC-MK2), as well as primary explants of embryonic and adult human tissue. L-15 medium can also be used for culturing viruses.