Rappaport-Vassilidis Broth

Rappaport-Vassiliadis Soya Broth is used for the enrichment and selective isolation of Salmonella spp. This medium is a modification of the original formulation by Rappaport et al. and has been formulated to exploit the full characteristics of Salmonella spp.

These characteristics include the ability to survive at relatively high osmotic pressure, to multiply at low pH values and greater resistance to malachite green.

This formulation also has the correct amount of magnesium chloride as previous formulations did not take into account the volume of displacement caused by dissolving large amounts of magnesium chloride in water.

This formulation has been shown to be superior to tetrathionate broth and selenite broth for the isolation of Salmonella spp. from meat products. Soya peptone provides the required carbon, nitrogen and vitamins. Potassium dihydrogen phosphate and di-potassium hydrogen phosphate act as buffers.

Magnesium chloride raises the osmotic pressure in the medium. Malachite green is an inhibitory substance.NB: This formulation is very hygroscopic and will produce a slight exothermic reaction when mixed with water.

Used for the enrichment and selective isolation of Salmonella spp.

Shelf Life (days): 1095 days

Storage Temp (°C): 10-30°C

Dehydrated Medium Appearance: Fine Powder

Prepared Medium Appearance: Liquid

Dehydrated Medium Colour: Pale Green

Prepared Medium Colour: Blue

Dehydrated PH: 5.2 ± 0.2

Prepared PH: 5.2 ± 0.2

Recommended Incubation: Aerobically at 41°C ± 0.5°C for 21-27 hours

Formula g/L

Soya peptone: 4.5

Sodium chloride: 7.2

Potassium dihydrogen phosphate: 1.26

Di-potassium hydrogen phosphate: 0.18

Magnesium chloride (Anhydrous): 13.58

Malachite Green: 0.036

Total: 26.75