MSRV Medium Base Modified

For the detection of Salmonella

MSRV:
selective medium for Salmonellae

See also ?Selective Supplement
for
MSRV Medium Base modified
Merck 9874?.

TECHNIQUE
Inoculate 3 drops (0.1 ml) of pre-enrichment or selective enrichment culture in three different spots on the surface of each MSRV medium plate.
Incubate at 42°C for 20-24 h.
READING
Whitish colonies sourrounded by an opaque halo on the inoculation spot confirm the presence of Salmonella.

Tryptone 4.59
Casein hydrolysate 4.59
NaCl 7.34
Monopotassium phosphate (Biokar) 1.47
Potassium dihydrogen phosphate (Merck) 1.47
Magnesium chloride anhydrous 10.93
Malachite green (oxalate) 0.037
Agar-agar 2.70
Final pH: 5.2 ± 0.2 at 25°C (Biokar)
Final pH: 5.4 ± 0.2 at 25°C. (Merck)

DESCRIPTION
Bacteriological efficiency is based on the ability of Salmonella to selectively migrate in the medium.
Salmonella form opaque halos of growth.
DIRECTIONS
Suspend 31.6 g/litre of distilled or demineralised water. Gently bring to the boil, stirring until complete dissolution.
Boil for 2 min.
Do not autoclave.
Aseptically dispense into 100 ml bottles.
Cool to 48°C.
Add the novobiocin selective supplement Merck 9874.
Pour Petri dishes.