Variants:
Mac Conkey agar:without salt - recommended for urocultures;
Mac Conkey agar:without crystal violet - less selective medium and allows growing of some Gram-positive cocci
other than enterococci.
Mac Conkey agar:with lactose replaced by sorbitol - used fpr EHEC (enterohaemorrhagic E. coli) strains isolation
which are sorbitol-negative and form colorless colonies. For medium preparation replace 10g lactose with 10g
sorbitol.
QUALITY CONTROL
MacConkey Agar
Escherichia coli ATCC 8739: red colonies, Salmonella typhimurium ATCC 14028: colourless colonies,
Pseudomonas aeruginosa ATCC 9027: colourless colonies, Staphylococcus aureus ATCC 6536: no growth.
MacConkey Broth
Escherichia coli ATCC 8739: turbid growth; acid and gas production,
Staphylococcus aureus ATCC®6538: turbid growth; no acid or gas production.
Mac Conkey agar:without salt - recommended for urocultures;
Mac Conkey agar:without crystal violet - less selective medium and allows growing of some Gram-positive cocci
other than enterococci.
Mac Conkey agar:with lactose replaced by sorbitol - used fpr EHEC (enterohaemorrhagic E. coli) strains isolation
which are sorbitol-negative and form colorless colonies. For medium preparation replace 10g lactose with 10g
sorbitol.
QUALITY CONTROL
MacConkey Agar
Escherichia coli ATCC 8739: red colonies, Salmonella typhimurium ATCC 14028: colourless colonies,
Pseudomonas aeruginosa ATCC 9027: colourless colonies, Staphylococcus aureus ATCC 6536: no growth.
MacConkey Broth
Escherichia coli ATCC 8739: turbid growth; acid and gas production,
Staphylococcus aureus ATCC®6538: turbid growth; no acid or gas production.
COMPOSITION
MacConkey Agar:
Peptone ....................................................................................... 20.0 g
Lactose ........................................................................................ 10.0 g
Bile salts ........................................................................................ 5.0 g
Sodium chloride ............................................................................. 5.0 g
Neutral red ................................................................................. 0.075 g
Agar ............................................................................................. 12.0 g
Distilled water ad 1000ml.
MacConkey Broth:
Peptone ....................................................................................... 20.0 g
Lactose ........................................................................................ 10.0 g
Bile salts ........................................................................................ 5.0 g
Sodium chloride ............................................................................. 5.0 g
Bromocresol purple ...................................................................... 0.01g
Distilled water ad 1000ml.
Adjust pH to 7.4 ± 0.2 at 25 ºC. Sterilize by autoclaving at 121 ºC for 15
minutes.
MacConkey Agar:
Peptone ....................................................................................... 20.0 g
Lactose ........................................................................................ 10.0 g
Bile salts ........................................................................................ 5.0 g
Sodium chloride ............................................................................. 5.0 g
Neutral red ................................................................................. 0.075 g
Agar ............................................................................................. 12.0 g
Distilled water ad 1000ml.
MacConkey Broth:
Peptone ....................................................................................... 20.0 g
Lactose ........................................................................................ 10.0 g
Bile salts ........................................................................................ 5.0 g
Sodium chloride ............................................................................. 5.0 g
Bromocresol purple ...................................................................... 0.01g
Distilled water ad 1000ml.
Adjust pH to 7.4 ± 0.2 at 25 ºC. Sterilize by autoclaving at 121 ºC for 15
minutes.
DESCRIPTION
Selective medium for the isolation of Salmonella, Shigella and coliform bacteria from faeces, urine, foods, water and
pathologic materials. MacConkey Broth is used as a presumptive medium for the detection of the coliforms from
water. MacConkey Agar is frequently used as selective media for Enterobacteriaceae. The growth of Gram-positive
germs is inhibited by the bile salts and the crystal violet. Lactose-positive germs form red colonies, lactose-negative
germs form colorless colonies.
Selective medium for the isolation of Salmonella, Shigella and coliform bacteria from faeces, urine, foods, water and
pathologic materials. MacConkey Broth is used as a presumptive medium for the detection of the coliforms from
water. MacConkey Agar is frequently used as selective media for Enterobacteriaceae. The growth of Gram-positive
germs is inhibited by the bile salts and the crystal violet. Lactose-positive germs form red colonies, lactose-negative
germs form colorless colonies.
| MacConkey medium |
(c) Costin Stoica
| Antibiogram |
| Encyclopedia |
| Culture media |
| Biochemical tests |
| Stainings |
| Images |
| Movies |
| Articles |
| Identification |
| Software |
| R E G N U M PROKARYOTAE |
| Back |