DMEM generally requires CO₂ concentration of:
Nutrient dense formulation of Dulbecco's Modified Eagle's Medium doubles concentration of essential and nonessential amino acids compared to MEM original Eagle minimal essential medium, quadruples vitamin concentrations niacinamide B3, pyridoxal B6, riboflavin B2 to support nucleotide and cofactor synthesis in rapidly proliferating transformed cells, increases glucose from 1 to 4.5 grams per liter to sustain high glycolytic flux, includes sodium pyruvate 110 mg per liter as additional carbon source, designed for plaque assays viral growth and high density cultures where cell number reaches 10^
Ref: Dulbecco & Freeman Virology 1959 DMEM 3700 mg/L bicarbonate requires 10% CO2; ATCC media guide MEM RPMI DMEM comparison.