To download in Adobe PDF format, click here For satisfactory biochemical identification, culture purity must be assured. Incubate at 35 C for 18-24h. Perform a Cytochrome Oxidase test. A blue colour developing within 2 min.
Salmonella is oxidase-negative.
Oxidase-positive cultures require no further testing and can be discarded. At least 6 tests can be performed consecutively on each strip. Handle used strips carefully since they contain live cultures. Discard such strips into a jar containing germicide. Using a heavy inoculum from the Nutrient Agar slant, inoculate a tube of Urea Broth or a Urea Agar Slant.