Cooked meat medium
- Cooked meat medium is a nutritious fluid broth used in the enrichment, rapid growth and maintenance of micro organisms especially anaerobes.
- It also enables species to be differentiated by their saccharolytic (acid and gas production with reddening of meat) and proteolytic (decomposition of meat with blackening) reactions
Composition of cooked meat medium
- Heart muscle………………………………454 gm/ltr
- Peptone…………………………………….10gm/ltr
- Lab-lemco powder………………………..10gm/ltr
- Sodium chloride…………………………..5gm/ltr
- Glucose (dextrose)………………………..2gm/ltr
Preparation of Cooked meat medium:
- Cooked meat medium can be prepared from dehydrated granules available from oxoid ltd and other manufacturer of culture media.
- Using a small tube or scoop pre-marked to hold 1 g of the granules, dispense the medium in 1 g amounts in screw-cap bottles or tubes.
- Add 1o ml of distilled water, mix and allow to soak for 5 minutes.
- Sterilizer the medium by autocalving (with caps loosened) at 121°C for 15 minutes.
- When cool, tighten the bottle caps.
- Date the medium and give it a batch number.
Quality control
- pH of medium:: this should be within the range pH 7.0-7.4. at room temperature.
- Test the medium by inoculating it with a swab of Clostridium sporogenes. Subculture on blood agar after 24 hours and 48 hours incubation.
- Store the medium in a cool dark place, making sure the bottle tops are tightly screwed.
Use of cooked meat medium:
- Depending on the specimen, cooked meat medium inoculated using a swab, Pasteur pipette or wire coop. if using a swab this should be inserted to the bottom of the container.
- Fresh cooked meat medium (with bottle cap loosened in a container of boiling water for 0-15 minutes to drive off any dissolved oxygen) is used for the culture of strict anaerobes
- *Allow the medium to cool to room temperature before inoculating it.