Preparing 2% agar
1. Determine how many plates of agar you need for a trial
2. Determine the volume of agar of each plate; the table below indicates the approximate volume of agar needed for each size of plate
Size of petri dish Volume of agar (mL)
Small (5cm) 10
Medium (10cm) 20
Large (20cm) 70
3. Calculate the total volume of agar
4. Prepare the agar; the following directions explain how to prepare 100mL
a. Weight out 2.00g of non-nutrient agar powder into a weigh boat
b. Measure out 100mL of deionized water into a 100mL graduated cylinder
c. Get a 200mL Erlenmyer flask; refer to the table below to see what flask is needed for the appropriate amount of solution
Volumed of media to be autoclaved: Use an Erlenmyer flask of:
100mL 250mL
200-300mL 500mL
400-800mL 1000mL
900-1000mL 2000mL
d. Add all of the powder to the flask, followed by deionized water. Use a Sharpie and label tape to label the flask with your name
e. Fill out Autoclave Request Form. Place flask(s) and the form on the counter labeled as such. Make sure to carefully describe any specific aspects to the pouring of the agar.
Careful! Make sure the volume of the flask is twice the volume of the media being autoclaved!
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