How to Pour Agar Plates

Agar plates are used by doctors and scientists of many different disciplines for culturing bacteria and diagnosing illness. Once the agar medium is prepared, pouring the plates becomes a relatively simple process if you follow the correct procedure.

Things You'll Need

• Molten agar medium
• Heat-proof gloves
• Petri dishes with lids
• Refrigerator

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Instructions

• 1

  Prepare the agar medium according to your needs. Remove it from the autoclave with your heat-proof gloves and swirl it to ensure a uniform consistency, then let the agar rest until it reaches 55 degrees Celsius.

• 2

  Remove the lids from your sterile petri plates and lay them out in a row on a workbench or table. About 300 mL of agar should make 10 to 12 plates.

• 3

  Take the flask of agar and pour a steady stream gently into each of the plates until they are halfway full. Try to minimize the introduction of air by pouring the agar from a low height and not moving or agitating the plates. Work quickly so that the agar does not harden in the flask.

• 4

  Allow the plates to cool on the workbench for 15 minutes, or until the agar solidifies. Stack them in groups of 5 and label the top plate with the type of medium and the date of pouring.

• 5

  Store the plates upside-down (the bottom of the plate pointing upwards) in a refrigerator to discourage condensation.