NUTRIENT AGAR

Cat. no. L20 Nutrient Agar, 16x100mm Tube, 5.5ml Slant 20 tubes/box
Cat. no. Q65 Nutrient Agar, 20x150mm Tube, 20ml Deep 20 tubes/box
Cat. no. Q84 Nutrient Agar, 20x150mm Tube, 20ml Pour Tube 100 tubes/box
Cat. no. W31 Nutrient Agar, 15x100mm Plate, 26ml (w/o plate label) 10 plates/bag
Cat. no. W51 Nutrient Agar, 15x100mm Plate, 26ml 10 plates/bag
Cat. no. W68 Nutrient Agar 1.5%, 15x100mm Plate, 26ml 10 plates/bag

INTENDED USE

Hardy Diagnostics Nutrient Agar formulations are general purpose growth media recommended for use in the isolation and cultivation of nonfastidious microorganisms.

SUMMARY

The American Public Health Association developed Nutrient Agar as a standard culture medium for growing a wide variety of microorganisms used in water, wastewater, food, and dairy testing.(2-4) The medium is still recommended today for the cultivation and maintenance of nonfastidious microorganisms from a broad spectrum of materials.(5,8,9,11-13)

Nutrient Agar is composed of pancreatic digest of gelatin and beef extract, which provide organic nitrogen compounds, long-chained fatty acids, carbohydrates, vitamins, and essential amino acids necessary for cell growth. Agar is the solidifying agent.

Nutrient Agar 1.5% is a modification of traditional Nutrient Agar and has a slightly more alkaline formulation. The medium also contains 0.8% sodium chloride, which helps maintain osmotic balance and protects against cell damage due to lysis.

FORMULA

Ingredients per liter of deionized water:*

Nutrient Agar:
Pancreatic Digest of Gelatin 5.0gm
Beef Extract 3.0gm
Agar 15.0gm

Final pH 6.8 +/- 0.2 at 25°C.

Nutrient Agar 1.5%:
Pancreatic Digest of Gelatin 5.0gm
Beef Extract 3.0gm
Sodium Chloride 8.0gm
Agar 15.0gm

Final pH 7.3 +/- 0.2 at 25°C.

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

STORAGE AND SHELF LIFE

Storage: Upon receipt store media in plates at 2-8°C. Media in tubes may be stored at 2-30°C. 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 and freezing.

PRECAUTIONS

PROCEDURE

Specimen Collection: Consult listed references for information on specimen collection. (1-5,7-9,13) Infectious material should be submitted directly to the laboratory without delay and protected from excessive heat and cold. If there is to be a delay in processing, the specimen should be inoculated onto an appropriate transport media and refrigerated until inoculation.

Method of Use: Inoculate and streak the specimen as soon as possible after collection. If the specimen to be cultured is on a swab, roll the swab over a small area of the agar surface. Streak for isolation with a sterile loop. Incubate tubes or poured plates aerobically at 35-37°C for 18-24 hours. Examine for colonial morphology.

Plates are primarily used for the isolation of pure cultures from specimens containing mixed flora. Tubed media are primarily used for the cultivation and maintenance of pure cultures.

INTERPRETATION OF RESULTS

Consult listed references for the identification of colony morphology and further biochemical tests required for identification.(1-5,7-9,11)

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
Staphylococcus epidermidis
ATCC ® 12228
A 18-24hr 35°C Aerobic Growth
Escherichia coli
ATCC ® 25922
A 18-24hr 35°C Aerobic Growth

User Quality Control

PHYSICAL APPEARANCE

Nutrient Agar should appear slightly opalescent, and light amber in color. Nutrient Agar 1.5% should appear clear to slightly opalescent, and light amber in color.

E. coli growing on Nutrient Agar

Escherichia coli (ATCC ® 25922) colonies growing on Nutrient Agar (Cat. no. W51). Incubated aerobically for 24 hours at 35°C.

S. epidermidis growing on Nutrient Agar

Staphylococcus epidermidis (ATCC ® 12228) colonies growing on Nutrient Agar (Cat no. W51). Incubated aerobically for 24 hours at 35°C.


Nutrient Agar

Uninoculated plate of Nutrient Agar (Cat. no. W51).

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

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

4. American Public Health Association. Standard Methods for the Examination of Water and Wastewater, APHA, Washington, D.C.

5. Association of Official Analytical Chemists. Official Methods of Analysissm, AOAC, Washington, D.C.

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

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

8. MacFaddin, J.F. 1985. Media for Isolation, Cultivation, Identification, Maintenance of Bacteria, Vol. I. Williams & Wilkins, Baltimore, MD.

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

10. Quality Assurance for Commercially Prepared Microbiological Culture Media, M22. Clinical and Laboratory Standards Institute (CLSI - formerly NCCLS), Wayne, PA.

11. 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.

081516gr