Buffered Peptone Water (ISO)

//Buffered Peptone Water (ISO)

Buffered Peptone Water (ISO)

SKU: KM0039 Category:

Formulated to ISO 6579, Buffered Peptone Water (BPW) is a pre-enrichment medium designed to help sub-lethally damaged Salmonella spp. recover before introducing them into a selective enrichment medium.
Enzymatic digest of casein is the source of the required nitrogen, carbon and vitamins. Sodium chloride maintains the osmotic balance in the medium. Di-sodium hydrogen phosphate and potassium di-hydrogen phosphate act as buffers in the medium. This nutritious medium is free from inhibitors and is well buffered to maintain pH 7.0 for the incubation period. Sub-lethal injury to Salmonella spp. occurs in many food processes and this pre-enrichment step greatly increases the chance of their recovery, especially if a low number of cells are present in a sample.


Additional Information

Shelf Life (days)

Storage Temp (°C)

Dehydrated Medium Appearance

Prepared Medium Appearance

Dehydrated Medium Colour

Prepared Medium Colour

Dehydrated PH

Prepared PH

Product Description

Organisms Ref. No Result
Salmonella typhimurium (productivity test) NCTC 12023 Growth
Salmonella enteritidis (productivity test) ATCC 13076 Growth
Staphylococcus aureus (productivity test) NCTC 12981 Growth
Escherichia coli (productivity test) NCTC 12241 Growth
Escherichia coli (maintenance viability test) NCTC 12241 Stable Viability*
Listeria monocytogenes (maintenance viability test) NCTC 11994 Stable Viability*
Staphylococcus aureus (maintenance viability test) NCTC 12981 Stable Viability*



Enzymatic digest of Casein 10.0
Sodium chloride 5.0
Di-sodium hydrogen phosphate 3.5
Potassium di-hydrogen phosphate 1.5
Total 20.0
*Adjusted/supplemented as required to meet performance requirements


Suspend 20g of the medium in one litre of deionised / purified water. Allow the medium to dissolve whilst mixing for 10 minutes. Dispense the required volume into the final containers and sterilise at 121°C for 15 minutes.