PDA Media Preparation
PDA Media Preparation
Principle:
PDA Media is used to grow fungi in the laboratory.The fungi may be pathogenic or non-pathogenic which may be identified on the basis of morphology and pigmentation.
Potato infusion and Dextrose is added to provide carbohydrate to support the luxuriant growth of fungi.
Agar acts as a solidifying agent.
Generally bacteria are also grown along with the required fungi . So, to prevent the growth of unwanted bacteria sterile 10% Tartaric acid is added.
Composition:-
Potato infusion 20 gm/100 ml
Dextrose 2 gm/100 ml
Agar-Agar 1.5 gm /100 ml
Distilled water Upto 100 ml
Preparation of Potato infusion:-
To prepare 1 lit PDA Media 200 gm potato is taken.
Washing of potatoes is required to remove dirt.
IPotatoes are peeled and diced.
Potato pieces are added to 1lit distilled water.
Boil for 20-25 minutes.
The extract is collected through the muslin cloth.
Instruments required :-
Glass beaker
Conical flask
Spatula
Measuring cylinder
pH meter
Digital weighing machine
Distilled water
Stirrer
Pipettes
Petri plates
Hot plate/ gas burner
Paper and rubber bands
0.1 N KOH or 0.1 N HCl
Procedure:-
Weight the ingredients with respect to volume of media ( e.g., 1 lit).
Suspend 200 gm potato infusion and 20 gm Dextrose in 900 ml dis. water.
Dissolve the components by using a stirrer and heating .
Adjust the pH to 5.6 by using 0.1 N HCl or 0.1 N KOH.
Make the final volume of 1 lit adding distilled water.
Transfer the solution into conical flasks.
Next add Agar-Agar with respect to the volume (15 GM's/lit or 3.75 GM's/ 250 ml ).
Then flasks are plugged by cotton and sealed with paper and rubber bands.
Autoclave for 20 minutes at 15 psi.
After cooling add Tartaric acid (10%) to prevent the growth of bacteria as well as to decrease the pH to about 3.5.
Mix well then pour into sterile Petri plates or test tubes for slants.
Storage:
Store in the dark at 2-8°C ( maximum time 7 days).
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