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Casman Medium Base

Casman Medium Base is used with blood for the isolation of Haemophilus influenzaeNeisseria gonorrhoeae and other fastidious microorganisms in a laboratory setting. Casman Medium Base is not intended for use in the diagnosis of disease or other conditions in humans.

In 1947, Casman described an infusion-free medium enriched with 5% blood for fastidious microorganisms incubated anaerobically. This medium replaced formulas containing fresh meat infusion and heated blood. Casman adjusted the formula after experiments revealed nicotinamide disrupted the action of a blood enzyme that inactivates V factor (NAD). The concentration of nicotinamide was lowered to support growth of Neisseria spp.

 

Formula Liter
Enzymatic Digest of Casein 5 g
Enzymatic Digest of Animal Tissue 5 g
Yeast Enriched Peptone 10 g
Beef Extract 3 g
Niacinamide 0.05 g
p-Aminobenzoic Acid 0.05 g
Dextrose 0.5 g
Corn Starch 1 g
Sodium Chloride 5 g
Agar 13.5 g

Final pH: 7.3 ± 0.2 at 25°C
Formula may be adjusted and/or supplemented as required to meet performance specifications.

Directions

  1. Suspend 43 g of the medium in one liter of purified water.
  2. Heat with frequent agitation and boil for one minute to completely dissolve the medium.
  3. Autoclave at 121°C for 15 minutes.
  4. After cooling medium to 50°C, aseptically add 5% sterile blood and 0.15% sterile water-lysed blood solution (one part blood to three parts water).

Order Details

Product # Product Description
7123A Casman Medium Base, 500 g
7123T Casman Medium Base, 5 kg