Product Overview
Potato Dextrose Agar is recommended for the cultivation and isolation of yeasts and molds from dairy and food products. Lowering the pH to 3.5 ± 0.1 inhibits bacterial growth and aids in the isolation of fungi. Agar medium used for the isolation, identification and cultivation of fungi. (Alpha Biosciences # P16-109-500gm)
Use: Agar medium used for the isolation, identification and cultivation of fungi.
Description: Potato Dextrose Agar is recommended for the cultivation and isolation of yeasts and molds from dairy and food products. Lowering the pH to 3.5 ± 0.1 inhibits bacterial growth and aids in the isolation of fungi.
Formula* per Liter:
- Potato Infusion .............................. 4.0g
- Dextrose .......................................20.0g
- Agar ............................................. 15.0g
Final pH: 5.6 ± 0.2 at 25.0°C
* Grams per liter may be adj. or formula supplemented to obtain desired performance
Preparation: Mix 39.0 grams of the medium in one Liter of purified water until evenly dispersed. Heat with repeated stirring and boil for one minute to dissolve completely. Distribute and autoclave at 121.0°C for 15 minutes. If desired, the pH of the medium can be adjusted to 3.5 ± 0.1 prior to pouring plates by the addition of 14 mL of sterile 10% tartaric acid to melted sterile medium cooled to 45°-50.0°C. Avoid reheating medium after the addition of the tartaric acid solution.
Quality Control Specifications:
- The powder is homogeneous, free flowing and light beige.
- Visually the prepared medium is clear to slightly hazy and pale to light yellow.
- Expected cultural response after 5 days at 25-30.0°C.
Organism Result
Aspergillus niger ATCC 16404 Woolly and black mycelium
Candida albicans ATCC 10231 Off-white creamy colonies
Saccharomyces cerevisiae ATCC 18790 Off-white creamy colonies
Trychophyton mentagrophytes ATCC 9533 Off white to tan & powdery
Storage: Store the sealed bottle containing the dehydrated medium at 2 to 30.0°C. Once opened and recapped, place the container in a low humidity environment at the same storage temperature. Protect it from moisture and light. The dehydrated medium should be discarded if it is not free flowing or if the color has changed from the original light beige color.