Answer

Weigh 70 grams of powder and add to 1 litre of deionised water. Allow to soak for 10 minutes or heat to dissolve completely, swirl to mix then sterilise by autoclaving at 121°C for 15 minutes. Cool to 45-50°C and pour into sterile Petri dishes. If acidified medium is required, adjust pH prior to pouring. Dry the set agar surface before use.
Store
Dehydrated culture media: 10-25°C.
Final medium: Plates - 7 days at 2-8°C
Capped containers – up to 1 month at 15-20°C in the dark.