Peptone Water, buffered ISO, 500 g

Liquid medium for the dilution and non-selective pre-enrichment from food samples.
FORMULA (*) in G/L :
Bacteriological peptone 10.00
Sodium chloride 5.00
Disodium phosphate (anhydrous) 3.5 (*1)
Potassium phosphate 1.50
Final pH 7.0 ±0.2 at 25 °C
(*1) Equivalent to 9.0 g of disodium hydrogen phosphate dodecahydrate.
(*)Adjusted and/or supplemented as required to meet performance criteria.
DIRECTIONS : Dissolve 20 g of powder in 1 l of distilled water. Distribute into suitable containers and sterilize by autoclaving at 121 °C for 15 minutes.
DESCRIPTION :
This formulation of buffered Peptone Water has the advantages of the two classical diluents used for food samples: it has the property of revitalitation of the peptone water and the pH change absorbing capacity of the phosphate buffer. The composition of this diluent is made according to the specification of the ISO standard 6579 for the detection of Salmonella in foods and other ISO standards (6785, 6887 and 8261).