Preparation of Rogosa-Agar Plate

Rogosa agar is a selective culture medium for the cultivation of lactobacilli. It can be purchased from several suppliers in a ready-to-use form (a mixture of all ingredients except acetic acid). Remember that there can be a slight variation in the composition of ready-to-use Rogasa agar from different suppliers and also the preparation procedure may vary slightly (the initial amount taken for preparation). Here we describe a procedure to prepare 20 – 25 Rogosa-agar plates using ThermoFisher scientific Rogosa agar ready-to-use premixed powder. To prepare 20 – 25 plates, you need 500 ml of Rogosa-Agar solution.


Reagents and solutions
Rogosa Agar (ThermoFisher Scientific, #CM0627B)
Deionized water

Equipment and disposables
Measuring cylinder
500 ml screw-capped bottle/conical flask
Weighing balance
Microwave oven/Hot plate
Magnetic stirrer
Disposable plastic 10-cm plates (sterile)


Preparation of 500 ml Rogosa-agar solution and plates (20 – 25 plates)


Step 1: Weigh out 41 g of Rogosa-agar powder in a 500 ml bottle. Add 500 ml water and a magnetic stirrer bead.

Step 2: Suspend the Rogosa-agar powder in water using a magnetic stirrer. Stir and suspend the powder in water nicely

Step 3: Microwave until all powder dissolves completely

Step 4: Add 660 µl glacial acetic acid. Mix and microwave for 2 min

Step 5: When the solution cools down to ≈ 50°C, pour the plate (add 20 – 25 ml solution per plate).

Step 6: Allow the plates to dehydrate overnight at room temperature.

Store the plates at 4°C.

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