# 429a: COLUMBIA BLOOD AGAR WITH CHARCOAL ## Main sol. 429a 1000 ml Columbia agar base 2 g Activated charcoal 4 % Horse blood 1. Add 2 g/l activated charcoal to the columbia agar base solution before autoclaving. Add 4% horse blood after cooling to 50°C. Swirl agar during suspending. To prevent dry agar surface, spread about 1 ml of sterile medium or water over the agar plates and briefly allow to soak into the agar before inoculation. Incubate Neisseria strains in a humid microaerobic atmosphere. Rehydrate pellets of freeze-dried ampoules in liquid medium 220, 215 or 1. ## Main sol. 1 5 g Peptone 3 g Meat extract 15 g Agar, for solid medium 1000 ml Distilled water 1. Adjust pH to 7.0. 2. For Bacillus strains the addition of 10.0 mg MnSO4 x H2O is recommended for sporulation. ## Main sol. 220 15 g Casein peptone 5 g Soy peptone 5 g NaCl 15 g Agar 1000 ml Distilled water 1. Adjust pH to 7.3. Medium is identical with Tryptone Soya Agar (Oxoid CM 131). ## Main sol. 215 37 g Brain heart infusion (Difco) 1000 ml Distilled water