Dextrose Agar

Specifications

Tryptose 10.000 G/L
Beef extract 3.000 G/L
Dextrose 10.000 G/L
Sodium chloride 5.000 G/L
Agar 15.000 G/L
Final pH (at 25°C) 7.3 ñ 0.2

Directions :
Suspend 43 grams in 1000 ml purified / distilled water. Heat to boiling to dissolve the medium completely.
Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes. Cool to 45-50°C. If desired, Blood Agar
can be prepared by the addition of 5% v/v sterile, defibrinated sheep blood into sterile Dextrose Agar. Mix
well and pour into sterile Petri plates.
Principle :
Meat Extract B and Tryptose provide nitrogen, amino acids and vitamins. Dextrose is a carbon source, and
the increased concentration is a distinguishing characteristic of this medium from other formulations used
as blood agar bases. Agar is a solidifying agent. Sodium chloride maintains osmotic equilibrium.
Supplementation with 5% blood provides additional growth factors for fastidious microorganisms.