CRITERION™ AZIDE DEXTROSE BROTH

Cat. no. C5050 CRITERION™ Azide Dextrose Broth 69.4gm
Cat. no. C5051 CRITERION™ Azide Dextrose Broth 500gm
Cat. no. C5052 CRITERION™ Azide Dextrose Broth 2kg
Cat. no. C5053 CRITERION™ Azide Dextrose Broth 10kg
Cat. no. C5054 CRITERION™ Azide Dextrose Broth 50kg

INTENDED USE

Hardy Diagnostics CRITERION™ Azide Dextrose Broth is used to detect the presence of streptococci in water, shellfish, sewage, and milk.

This dehydrated culture medium is a raw material intended to be used in the making of prepared media products, which will require further processing, additional ingredients, or supplements.

SUMMARY

Azide Dextrose Broth is recommended by the APHA for the isolation of fecal streptococci.(2) Various workers indicated that sodium azide could be used to inhibit gram-negative microorganisms while allowing the growth of gram-positive microorganisms, particularly Streptococcus spp. Azide Dextrose Broth has also been used for isolation of streptococci in foodstuffs and other specimens of sanitary significance as an indication of contamination.

Beef extract and tryptose serve as sources of carbon, nitrogen, vitamins and minerals. Dextrose serves as an energy source and sodium chloride is added to maintain the osmotic equilibrium. Sodium azide inhibits cytochrome oxidase in gram-negative bacteria.

FORMULA

Gram weight per liter: 34.7gm/L
Casein Peptone 7.5gm
Animal Tissue Peptone 7.5gm
Dextrose 7.5gm
Sodium Chloride 7.5gm
Beef Extract 4.5gm
Sodium Azide 0.2gm

Final pH 7.2 +/- 0.2 at 25ºC.

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

STORAGE AND SHELF LIFE

Store the sealed bottle(s) containing dehydrated culture medium at 2-30ºC. Dehydrated culture medium is very hygroscopic. Keep lid tightly sealed. Protect dehydrated culture media from moisture and light. The dehydrated culture media should be discarded if it is not free-flowing or if the color has changed from its original light beige.

Store the prepared media at 2-8ºC.

PRECAUTIONS

METHOD OF PREPARATION FOR DEHYDRATED CULTURE MEDIA

1. Suspend 34.7gm of the dehydrated culture media in 1 liter of distilled or deionized water.

2. Heat as needed to dissolve completely.

3. Autoclave at 121ºC. for 15 minutes.

PROCEDURE AND INTERPRETATION OF RESULTS

For information on procedures and interpretation of results, consult listed references or refer to the prepared media Instructions for Use (IFU) for Cat. No. K87.

LIMITATIONS

CRITERION™ Azide Dextrose Broth is used to detect presumptive evidence of fecal contamination. Further biochemical testing must be done for confirmation.

For inoculum sizes of 10ml or larger, use double strength medium to prevent dilution of ingredients.

MATERIALS REQUIRED BUT NOT PROVIDED

Standard microbiological supplies and equipment such as autoclaves, incinerators, and incubators, etc., are not provided.

QUALITY CONTROL

Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Enterococcus faecalis
ATCC ® 29212
A 24-48hr 35°C Aerobic Heavy growth
Escherichia coli
ATCC ® 25922
B 24-48hr 35°C Aerobic Inhibited

User Quality Control

PHYSICAL APPEARANCE

CRITERION™ Azide Dextrose Broth powder should appear homogeneous, free-flowing, and light beige in color. Visually the single strength prepared broth should appear clear, and light to medium amber in color; double strength should appear clear, and medium to dark amber in color.

REFERENCES

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

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


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

050916gr