Measure Water
Measure 500ml de-ionized water in a graduated cylinder.
Fill Jar
Pour 500ml de-ionized water from the graduated cylinder into a 1L glass jar and add a stir bar.
Heat Water
Place jar on a hot plat at 30C with the cap loosely on and heat until bottle shows condensation or is warm to the touch.
Weigh Agar
Using a weigh boat and scoop, weigh 19.5g potato dextrose agar. For water agar and bacteriological water agar, measure 10g bacto agar per 500mL. For bacteriological agar, also measure 0.25 g/500mL Penicilin G and 0.25g/500mL Streptomycin Sulfate to be used after media has been autoclaved.
Create a Vortex
Set magnet bar to about 600 or until the bar rapidly spins, creating a vortex.
Mix Agar
Slowly add agar and mix until dissolved.
Prepare Jar
Screw the cap of the jar fully tight and then loosen one half turn. Add a piece of auto clave tape to the cap and place jar in a plastic container.
Autoclave
Place container in an autoclave and heat to 121C for 15 minutes.
Cool Agar
Carefully remove container from the autoclave using gloves. Place jar in water bath and allow to cool.
Prepare Ventilation Hood
While jars are cooling, sanitize the inside of the ventilation hood using Kim wipes and 70% ethanol.
Prepare Plates
Prepare petri plates to be poured by carefully removing the plastic sleeve they are in. Save the sleeve for later.
Label Plates
Use the key above and colored markers to label plates.
Set Up Hood
Once the agar is cool enough to hold, move a jar into the hood and remove the cap inside. Split plates into stacks of five. If you are making PDA or WA, you are ready to pour plates. If you are making AWA, place a hot plate with stirring capacity in the hood. Slowly add Penicilin G and Streptomycin and stir thoroughly before pouring plates.
Pour Media
Pour media into five petri plates leaving a clear pathway for air flow. Gently shake plates to ensure media reaches all edges. Repeat until all media is poured (500ml makes 25 plates).
Store Plates
Place plastic sleeve back over plates and allow to cool overnight. Seal the plastic and place in refrigerator for later use.
