Creatinine Dextrose Bromothymol Blue Thymine (CDBT) Agar

For differentiation of C. neoformans var. neoformans and C. neoformansvar. grubii (Irokanulo et al. 1994).

Solution A

Creatinine 1 g

Dextrose 0.5 g

KH2PO4 1 g

MgSO4.7H2O 0.5 g

Thymine 0.1 g

Distilled water 980 mL

Dissolve ingredients in small beaker and adjust pH to 5.6

Store in refrigerator.

Solution B (aqueous bromothymol blue)

Bromothymol Blue 0.4 g

0.01N NaOH 64 mL

Distilled water 36 mL

Dissolve the Bromothymol Blue in the NaOH

Add to the water.

To prepare medium (1 litre for plates):

Solution A 980 mL Solution B 20 mL

Bacto agar (BD 214010) 20 g

Autoclave to 121C for 15 minutes, cool to 48C and dispense as plates.