Buffered Peptone Water (ISO), pH 7.0

Buffered Peptone Water (ISO), pH 7.0 is used for the non-selective pre-enrichment of Salmonella spp. from food in a laboratory setting. Buffered Peptone Water (ISO), pH 7.0 is not intended for use in the diagnosis of disease or other conditions in humans.

Edel and Kamelmacher found that food preservation techniques involving heat, desiccation, preservatives, high osmotic pressure, or pH changes cause sublethal injury to Salmonellaspp. Pre-enrichment in a non-selective medium allows for repair of cell damage and facilitates the recovery of Salmonella. Lactose Broth is frequently used for this purpose, but it may be detrimental to recovering Salmonellae. Buffered Peptone Water (ISO), pH 7.0, maintains a high pH over the pre-enrichment period, allowing repair of injured cells that may be sensitive to a low pH. The pH factor is particularly important for vegetable specimens, which have a low buffering capacity. Buffered Peptone Water conforms with the formula specified in International Organization for Standardization (ISO), ISO/TS 11133-2:2003.


Formula Liter
Peptone 10 g
Sodium Chloride 5 g
Disodium Phosphate 3.5 g†
Monopotassium Phosphate 1.5 g

  † Equivalent to 9.0 g of disodium hydrogen phosphate dodecahydrate
Final pH: 7.0 ± 0.2 at 25°C
Formula may be adjusted and/or supplemented as required to meet performance specifications.


  1. Dissolve 20 g of the medium in one liter of purified water.
  2. Heat with frequent agitation to completely dissolve the medium, if necessary.
  3. Autoclave at 121°C for 15 minutes.

Order Details

Product # Product Description
7417A Buffered Peptone Water (ISO), pH 7.0, 500 g
7417T Buffered Peptone Water (ISO), pH 7.0, 5 kg