Dulbecco's Modified Eagle Medium /Nutrient Mixture F12 Ham (DMEM/F12, 1:1 mixture) was originally formulated for rat neuroblastoma cells and MDCK cells. DMEM/Nutrient Mixture F-12 Ham is with Lglutamine, sodium bicarbonate, 15mM HEPES buffer and trace elements. Dulbeccoâs Modified Eagle Medium / Nutrient Mixture F12 Ham (DMEM/F12, 1:1 mixture) was originally formulated for rat neuroblastoma cells and MDCK cells. The mixture is extremely nutritious and supports growth of a wide variety of cells including certain epithelial, endothelial and granulosa cells. AL139A is DMEM/Nutrient Mixture F-12 Ham with Lglutamine, sodium bicarbonate, 15mM HEPES buffer and trace elements. HEPES, a zwitterionic buffer having a pKa of 7.3 at 37ºC prevents the initial rise in pH that tends to occur at the initiation of a culture and increases the buffering capacity of the medium.