Brand:
Thermo ScientificTM OxoidTM
Detect and enumerate coliform organisms, including Escherichia coli, while isolating and detecting Salmonella and Shigella spp. in both clinical and food specimens using Thermo Scientific⢠Oxoid⢠MacConkey Agar No.3. A modification of the original MacConkey medium by the addition of selected bile salts, the medium gives improved differentiation of coliforms and non-lactose fermenting organisms while completely inhibiting Gram-positive cocci.
MacConkey Agar No.3, Oxoid Composition
| Typical Formula* |
gm/litre
|
| Peptone |
20.0
|
| Lactose |
10.0
|
| Bile salts No.3 |
1.5
|
| Sodium chloride |
5.0
|
| Neutral red |
0.03
|
| Crystal violet |
0.001
|
| Agar |
15.0
|
| pH 7.1 ± 0.2 @ 25°C |
|
MacConkey Agar, Oxoid Preparation:
Suspend 51.5g in 1 litre of distilled water. Bring to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes.
Storage conditions and Shelf life
The dehydrated medium should be stored at 10-30°C and used before the expiry date on the label.
Store the prepared medium at 2-8°C.