MacConkey Agar without Crystal Violet is used for the isolation and differentiation of Gram-negative enteric bacilli and is not intended for use in the diagnosis of disease or other conditions in humans.
A selective medium for the isolation of bile tolerant organisms from sewage and foodstuffs. Bile-tolerant Gram positive organisms as well as Gram negative organisms will grow on this medium. This formula is recommended by W.H.O. and other bodies for the examination of water and milk. Some strains of Proteus spp. will spread on this medium making interpretation difficult, for this reason MacConkey Agar (without salt) may be preferred as it is less prone to this phenomenon.
Formula | Liter |
Peptone | 20.0 g/L |
Lactose | 10.0 g/L |
Bile Salts | 5.0 g/L |
Sodium Chloride | 5.0 g/L |
Neutral Red | 0.05 g/L |
Agar | 12.0 g/L |
Final pH: 7.4 ± 0.2 at 25°C
Formula may be adjusted and/or supplemented as required to meet performance specifications.