Cooked Meat Medium

LAB 127

Description

This is a complete version of Robertson's Cooked Meat Broth which was designed to grow all anaerobes found in battlefield wounds during the First World War. The medium is based on LAB M Cooked Meat Granules - LAB 24 and Nutrient Broth - LAB 14.

Method for reconstitution

Use a calibrated scoop to distribute 0.9 gram amounts of granules into tubes or bottles. Add 10ml deionised water. Sterilise at 121˚C for 10 minutes. Use proportionately more granules and water if greater depths of medium are required.

Appearance: Granules covered in slightly opalescent pale yellow liquid.

pH: 7.0 ± 0.2

Inoculation: Samples or swabs directly into the medium.

Incubation: 37˚C for mesophiles, appropriate temperature for thermophiles.

Interpretation: Reddening of meat - saccharolytic organism - Blackening and digestion - proteolytic organism.

References

Robertson, M., (1916) J. Path. & Bact. 20 327-349.

Method for reconstitution

Weigh 45.5 grams of powder, disperse in 1 litre of deionised wa Allow to soak for 10 minutes, swirl to mix, then bring to the boil w frequent stirring. When the medium boils up into the neck of flask, quickly remove from the source of heat and allow the frot subside. Return to the heat and allow the foam to boil up into the n of the flask once more. Remove at once and cool to 47˚C app before pouring plates. Dry the surface before inoculation. DO N REMELT OR AUTOCLAVE THIS MEDIUM.

Appearance: Pale pink, translucent, a fine precipitate desoxycholate may be present which may clear if the pH is increa by the growth of organisms.

pH: 7.0 ± 0.2

Minimum Q.C. organisms: Salmonella sp. NCIMB 50076 E. coli NCIMB 50034

Storage of Prepared Medium: Plates - up to 7 days at 2-8˚C in the dark.

Inoculation: Surface, streaking for single colonies.

Incubation: 37˚C for 18-24 hours aerobically.