POTATO DEXTROSE AGAR (PDA)

Cat. no. G94 Potato Dextrose Agar with TA (Tartaric Acid), 15x60mm Plate, 13ml 10 plates/bag
Cat. no. W93 * Potato Dextrose Agar with Chlortetracycline, 15x100mm Plate, 26ml 10 plates/bag
Cat. no. W94BX Potato Dextrose Agar with Chloramphenicol, 15x100mm Plate, 28ml 100 plates/box
Cat. no. W96 * Potato Dextrose Agar with TA (Tartaric Acid), 15x100mm Plate, 28ml 10 plates/bag
Cat. no. W96R* Potato Dextrose Agar with TA (Tartaric Acid), 15x100mm Red-Tinted Plate, 28ml 10 plates/bag

INTENDED USE

Hardy Diagnostics Potato Dextrose Agar with TA (Tartaric Acid) is recommended for the microbial examination of food and dairy products. Potato Dextrose Agar with Chlortetracycline is recommended for the microbial enumeration of yeast and mold from cosmetics.(8,9,12) Potato Dextrose Agar with Chloramphenicol is recommended for the selective cultivation of fungi from mixed samples.

* Products are not intended to be used for the diagnosis of human disease.

SUMMARY

Potato Dextrose Agar consists of potato infusion and dextrose. Potato infusion provides a nutrient base for luxuriant growth of most fungi. Dextrose serves as a growth stimulant. The incorporation of tartaric acid (TA) in the medium lowers the pH to 3.5, thereby inhibiting bacterial growth. Chloramphenicol acts as a selective agent to inhibit bacterial overgrowth of competing microorganisms from mixed specimens, while permitting the selective isolation of fungi.

In Standard Methods for the Examination of Dairy Products, the American Public Health Association (APHA) recommends Potato Dextrose Agar with TA (Tartaric Acid) for determining yeast and mold counts from butter, margarine and related products.(8)

The U.S. Food & Drug Admistration (FDA) recommends Potato Dextrose Agar with Chlortetracycline for the evaluation of yeast and mold from cosmetic products.(12)

FORMULA

Ingredients per liter of deionized water:*

Dextrose 20.0gm
Potato Extract 4.0gm*
Agar 15.0gm

*4.0gm of potato extract is equivalent to 200gm of potato infusion.

In addition, Potato Dextrose Agar with Chlortetracycline contains:

Chlortetracycline 40.0mg

In addition, Potato Dextrose Agar with Chloramphenicol contains:

Chloramphenicol 25.0mg

Final pH of 5.6 +/- 0.2 at 25ºC.

In addition, Potato Dextrose Agar with TA contains:

Tartaric Acid 1.4gm

Final pH of 3.5 +/- 0.3 at 25ºC.

* Adjusted and/or supplemented as required to meet performance criteria.

STORAGE AND SHELF LIFE

Storage: Upon receipt, store at 2-8ºC away from direct light. Media should not be used if there are any signs of deterioration (shrinking, cracking, or discoloration), contamination, or if the expiration date has passed. Product is light and temperature sensitive; protect from light, excessive heat, moisture, and freezing.

PRECAUTIONS

For cat. nos. G94 and W94BX

For cat. nos. W93, W96 and W96R.

PROCEDURE

Specimen Collection: Consult listed references for information on specimen collection.(1-5)

When using Potato Dextrose Agar with TA (Tartaric Acid), Potato Dextrose Agar with Chlortetracycline or Potato Dextrose Agar with Chloramphenicol, refer to listed references for the appropriate method of use and interpretation.(2,4,6-12)

INTERPRETATION OF RESULTS

Consult listed references for information regarding the interpretation of growth of fungal species.(2-12)

LIMITATIONS

MATERIALS REQUIRED BUT NOT PROVIDED

Standard microbiological supplies and equipment such as loops, other culture media, swabs, applicator sticks, incinerators, and incubators, etc., as well as serological and biochemical reagents, are not provided.

QUALITY CONTROL

Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Potato Dextrose Agar with Chlortetracycline (Cat. no. W93)
Trichophyton mentagrophytes
ATCC ® 9533
G 5-7 days 20-25°C Aerobic Growth; may take up to 7 days
Candida albicans
ATCC ® 10231
A 24-48 hrs 20-25°C Aerobic Growth; smooth white colonies
Staphylococcus aureus
ATCC ® 25923
B 24 hrs 35°C Aerobic Inhibited
Escherichia coli
ATCC ® 25922
B 24 hrs 35°C Aerobic Inhibited

Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Potato Dextrose Agar with TA (Cat. nos. G94, W96, and W96R)
Trichophyton mentagrophytes
ATCC ® 9533
G 5-7 days 20-25°C Aerobic Growth; may take up to 7 days
Trichophyton rubrum
ATCC ® 28188
G 3-4 wks 20-25°C Aerobic Growth seen in 7 days; may take 3-4 weeks for red color on reverse side of colony to be visible
Aspergillus brasiliensis
ATCC ® 16404
G 1-5 days 20-25°C Aerobic Growth; may take up to 7 days
Candida albicans
ATCC ® 10231
A 1-3 days 20-25°C Aerobic Growth; may take up to 7 days

Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Potato Dextrose Agar with Chloramphenicol (Cat. no. W94BX)
Candida albicans
ATCC ® 10231
A 24-48 hrs 20-25°C Aerobic Growth; may take up to 7 days
Aspergillus brasiliensis
ATCC ® 16404
G 1-5 days 20-25°C Aerobic Growth; may take up to 7 days
Escherichia coli
ATCC ® 25922
B 24hrs 35°C Aerobic Partial to complete inhibition

USER QUALITY CONTROL

Physical Appearance

Potato Dextrose Agar with TA, Potato Dextrose Agar with Chlortetracycline and Potato Dextrose Agar with Chloramphenicol should appear slightly opalescent, and light amber in color, with no precipitate, chips, or debris.

REFERENCES

1. Anderson, N.L., et al. Cumitech 3B; Quality Systems in the Clinical Microbiology Laboratory, Coordinating ed., A.S. Weissfeld. American Society for Microbiology, Washington, D.C.

2. Jorgensen., et al. Manual of Clinical Microbiology, American Society for Microbiology, Washington, D.C.

3. Tille, P., et al. Bailey and Scott's Diagnostic Microbiology, C.V. Mosby Company, St. Louis, MO.

4. Isenberg, H.D. Clinical Microbiology Procedures Handbook, Vol. I, II & III. American Society for Microbiology, Washington, D.C.

5. Koneman, E.W., et al. Color Atlas and Textbook of Diagnostic Microbiology. J.B. Lippincott Company, Philadelphia, PA.

6. St. Germain, Guy, et al. 1996. Identifying Filamentous Fungi. Star Publishing Company, Belmont, CA.

7. Campbell, M.C. and J.L. Stewart. 1980. The Medical Mycology Handbook, John Wiley and Sons, New York, NY.

8. American Public Health Association. Standard Methods for the Examination of Dairy Products. APHA, Washington, D.C.

9. APHA Technical Committee on Microbiological Methods for Foods. Compendium of Methods for the Microbiological Examination of Foods. APHA, Washington, D.C.

10. Association of Official Analytical Communities. Official Methods of Analysis™. AOAC, Washington, D.C.

11. Robell and Taplin. 1970. Dermatophytes, U. of Miami Press.

12. U.S. Food and Drug Administration. Bacteriological Analytical Manual. AOAC, Arlington, VA.
http://www.fda.gov/Food/FoodScienceResearch/LaboratoryMethods/ucm2006949.htm.

ATCC is a registered trademark of the American Type Culture Collection.

021916hh