Formulation consists of various inorganic salts, vitamins, amino acids and others.

• Store medium at 2 to 8 °C in the dark when not in use
• pH: 7.0 to 7.4
• Osmolality: 260 to 320 mOsm/kg
• Endotoxin: ≤0.5 EU/ml

Modified to contain Earle's balanced salt solution, non-essential amino acids, 2 mM L-glutamine, 1 mM sodium pyruvate, and 1500 mg/l sodium bicarbonate.

This reduced level of sodium bicarbonate (NaHCO₃, 1.5 g/l) is intended for use in 5% CO₂ in air. Additional sodium bicarbonate may be required for use in incubators containing higher percentages of CO₂.