CGB Agar
CGB (L-Canavanine, glycine, 2 bromthymol blue) Agar.
For distinction between Cryptococcus neoformans var. neoformans and Cryptococcus neoformans var. gattii (Kwon-Chung et al., 1982).
Solution A
Ingredients:
| Glycine | 10 g |
| KH2PO4 | 1 g |
| MgSO4 | 1 g |
| Thiamine HCl | 1 mg |
| L-canavanine sulphate | 30 mg |
| Distilled water | 100ml |
Method:
1. Dissolve ingredients in small beaker and adjust pH to 5.6
2. Filter sterilize solution using 0.22 um filter.
3. Store in refrigerator.
Solution B (Aqueous Bromthymol Blue)
Ingredients:
| Bromthymol blue | 0.4 g |
| 0.01N NaOH | 64 ml |
| Distilled water | 36 ml |
1. Dissolve the Bromthymol Blue in the NaOH
2. Add to this the water.
To prepare medium (1L for plates)
| Distilled water | 880 ml |
| Solution B | 20 ml |
| Bacto agar | 20 g |
1. Autoclave to 121C for 15 minutes, cool to 48C.
2. For plates add 100 ml of the filtered solution A and mix. Dispense in plates.
