Contains L-glutamine. Developed for the support of cell growth in non-CO2-equilibrated environments. L15 formulations were developed without a sodium bicarbonate buffer system. L15 medium is buffered by phosphates and free-base amino acids (L-arginine primarily, but also L-histidine and L-cysteine). Production of acidic metabolites is reduced by replacing glucose with galactose and sodium pyruvate. Reported to support the growth of HEP-2, monkey kidney cells and primary explants of embryonic and adult human tissue.