توضیحات
Preparation
- Shake the container well. Dissolve 35 grams of the medium powder in one liter of distilled water.
- Autoclave the culture medium at 121 degrees Celsius for 15 minutes.
- Pour the culture medium into test tubes containing Durham tubes.
STORAGE
The medium container should be kept tightly closed and stored at a temperature below 35°C, and the prepared medium should be stored at a temperature of 2-8°C. The best time to use is before the expiration date printed on the product label.
Test
Test
Test
- Prepare the sample according to the type of sample and the relevant standard protocol, and inoculate it onto the culture medium.
- Incubate the inoculated tubes for 18-24 hours at 35±2°C under aerobic conditions.
Results and Interpretation
Lactose fermenting bacteria ferment the lactose present in the medium and produce acid, which turns the color of the culture medium to yellow. The gas produced by this fermentation accumulates in the Durham tubes. Non-lactose fermenting bacteria create turbidity during growth but are unable to produce acid and gas.
The production and accumulation of gas in Durham tubes, as well as the production of acid which leads to yellowing of the culture medium, can be an indication of the presence of coliform and E. coli bacteria in the sample. The production of acid without gas production can be a sign of the presence of coliforms and the absence of E. coli.
Note
- The MacConkey broth is also used for the rapid identification of E.coli bacteria that produce shiga toxin in fecal samples.
