Dissolve peptone and lactose in 500 ml distilled water. Add 20 g dehydrated oxgall dissolved in 200 ml distilled water. The pH of this solution should be 7.0-7.5. Mix and add water to make 975 ml. Adjust pH to 7.4. Add 13.3 ml 0.1% aqueous brilliant green in distilled water. Add distilled water to make 1 liter.

Dispense into fermentation tubes, making certain that fluid level covers inverted vials.

Autoclave 15 min at 121°C. Final pH, 7.2 ± 0.1.

Hypertext updated by rim/cjm 2005-OCT-21