VRBD AGAR (VIOLET RED BILE DEXTROSE)SEG HARM EP/USP/JP MERCK 500GR
Mode of Action
Crystal violet and bile salts inhibit the accompanying bacterial flora. Degradation of glucose is accompanied by production of acid, which is indicated by a colour change to red and by zones of precipitated bile acids surrounding the colonies. All Enterobacteriaceae are detected as they all degrade glucose to acid. The
culture medium is not, however, absolutely specific for these organisms as some other accompanying bacteria (e.g. Aeromonas) also show these reactions.
Typical Composition (g/litre)
Peptone from gelatine 7.0;
yeast extract 3.0;
sodium chloride 5.0;
bile salt mixture 1.5;
neutral red 0.03;
crystal violet 0.002;
Suspend 39.5 g in 1 litre of demin. water and heat to boiling with frequent stirring until completely dissolved. Afterwards do not boil more than 2 minutes.
Do not autoclave! Do not overheat!
pH: 7.3 ± 0.2 at 25 °C.
The prepared medium is clear and dark red.
Incubation: for 24 hours at 35 °C aerobically.
The identity of suspected Enterobacteriaceae colonies should be confirmed by further tests.
Imagem meramente ilustrativa.