This dehydrated culture medium is ideal for cultivation and isolation of yeasts and molds from dairy products and other food products. Lowering the pH to 3.5 ± 0.1 inhibits bacterial growth and aids in the isolation of fungi. Product supplied with Lot Number, Expiration Date, and procedure on how to prepare the agar medium.
Formula (per liter)...
- Potato Infusion (dehydrated): 4.0 g
- Dextrose: 20.0 g
- Agar: 15.0 g
To rehydrate Potato Dextrose Agar...
- Suspend 39 grams in a clean beaker with 1000ml of cold, distilled water. This will yield 50 plates (15 x 100mm). Use 19.5 grams in 500ml of water for a 25 plate yield.
- Heat to boiling to dissolve the agar completely. Stir with a flame-sterilized glass stir rod to help agar mix better.
- [Optional Step] Once mixed, transfer the suspension into a clean flask and sterilize in an autoclave for 15 minutes at 15 pounds pressure (121°C). (A pressure cooker can also be used). Remove from autoclave and let cool.
- Remove from heat. When agar has cooled to about 45°C (check temperature using a sterilized lab thermometer) it is ready to pour. Pour into sterile petri plates about 1/4” deep and allow to set. Once the prepared plates have gelled, they can be used or refrigerated for future use. Store plates upside down with potato dextrose agar in upper half of plate. This will prevent condensation from dripping down and contaminating the agar growing surface.
