Buffered Peptone Water

Description

Use and Description:

A pre-enrichment medium design to recovery of sublethally damaged salmonella before introducing them into a selective medium. Use as a pre-enrichment medium for the isolation of salmonella spp. from various food sources.

Composition per litre:

Peptone……………………………………………….10.0 g

Sodium chloride…………………………………….5.0 g

Disodium hydrogen phosphate………….…..3.5 g

Potassium dihydrogen phosphate……….…1.5 g

Final pH of the ready to use medium: 7.0-7.2 +/- 0.2

Medium preparation:

Add 20.0 grams of dehydrated culture medium to 1 litre of distilled water. Heat with repeated stirring and boil for one minute to dissolve completely. Distribute and autoclave at 121°C for 15 minutes.

Quality specifications:

Dehydrated medium: homogeneous, light beige fine powder.

Ready to use medium: clear and pale yellow.

Microbiological response:

Storage:

Dehydrated medium should be stored between 10 to 25°C. Once opened, place the container in a dark, dry place. The dehydrated medium should not be used if there is any lump or if the colour has changed from the original.