Potato Dextrose Agar

Description

Use and description:

For the cultivation and enumeration of yeasts and moulds from dairy and food products. In order to suppress bacterial growth acidify the medium to pH 3.5.

Composition per litre:

Potato extract……………………………….4.0 g

Dextrose……………………………………..20.0 g

Agar……………………………………………15.0 g

Final pH of the ready to use medium: 5.6 ± 0.2

Medium preparation:

Add 39.0 grams of dehydrated culture medium to 1 litre of distilled water. Heat with repeated stirring and boil for one minute to dissolve completely. Distribute and autoclave at 121°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% lactic acid to melted sterile medium cooled to 45-50°C. Avoid reheating the medium after the addition of the acid.

Quality specifications:

Dehydrated medium: homogeneous, light beige fine powder.

Ready to use medium: clear to slightly hazy and pale to light yellow.

Microbiological response:

Storage:

Dehydrated medium should be stored between 10 to 25°C. Once opened, place the container in a dark, dry place. The dehydrated medium should not be used if there is any lump or the colour has changed from the original.

500g wrapped pots