EZ Prep, Buffered Peptone Water

Buffered Peptone Water is used for the non-selective pre-enrichment of Salmonella spp. from food in a laboratory setting. Buffered Peptone Water 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 maintains a high pH over the pre-enrichment period and allows in repair of injured cells that may be sensitive to low pH. This is particularly important for vegetable specimens which have a low buffering capacity. Buffered Peptone Water is used in standard methods.

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

Final pH: 7.2 ± 0.2 at 25°C
Formula may be adjusted and/or supplemented as required to meet performance specifications.


  1. Add 25 g sample to sample bag.
  2. Add contents of Acumedia EZ Prep packet to sample bag.
  3. Add 225 mL sterile purified water.
  4. Mix thoroughly (a stomacher can be used).