Charcoal Agar

Charcoal Agar

SKU: KM0185 Category:

Charcoal agar is used for the cultivation of fastidious organisms, particularly Bordetella pertussis. Charcoal agar is prepared according to the formulation developed by Mishulow, Sharpe and Cohen. This medium is an efficient substitute for Bordet-Gengou agar in the production of B. pertussis vaccines and can be used as a maintenance medium for stock cultures of Bordetella spp.
Beef extract and peptone provide the required nitrogen, carbon and vitamins. Sodium chloride maintains the osmotic balance. Starch and charcoal help in absorbing toxic metabolites that are produced during growth of the organism. Nicotinic acid is an essential growth factor for the growth of Bordetella spp. The addition of cephalexin (LS0018) inhibits accompanying contamination in the samples.
NB: This is a basic medium only and contains no additional supplement. If cephalexin is added, it should be noted, that although coliforms are inhibited by this medium, Pseudomonas aeruginosa and some fungi will grow.

Related Supplements :
LS0018 Bordetella Selective Supplement

Additional Information

Shelf Life (days)

Storage Temp (°C)

Dehydrated Medium Appearance

Prepared Medium Appearance

Dehydrated Medium Colour

Prepared Medium Colour

Dehydrated PH

Prepared PH

Product Description

Organisms Ref. No Result
Bordetella pertussis NCTC 10739 Growth, grey colonies
Staphylococcus aureus NCTC 12981 Inhibited
Klebsiella pneumoniae NCTC 9633 Inhibited

 

Formula*

g/L
Beef extract 10.0
Peptone 10.0
Starch 10.0
Charcoal 4.0
Sodium chloride 5.0
Nicotinic acid 0.001
Agar 12.0
Total 51.0
*Adjusted/supplemented as required to meet performance requirements

Preparation

Suspend 51g of the medium in one litre of deionised / purified water. Allow the medium to soak whilst mixing for 10 minutes. Heat with frequent agitation and boil for one minute to completely dissolve the medium. Sterilise at 121°C for 15 minutes. Cool to 45-50°C and aseptically add 100 ml/L of horse blood and 2 vials of Bordetella Selective Supplement (LS0018), if required. Homogenize gently and dispense into appropriate sterile containers.

NB: Frequently mix the medium during dispensing to ensure the charcoal is kept in suspension.