CRITERION™ D/E NEUTRALIZING BROTH

Cat. no. C7370 CRITERION™ D/E Neutralizing Broth 84.8gm
Cat. no. C7371 CRITERION™ D/E Neutralizing Broth 500gm
Cat. no. C7372 CRITERION™ D/E Neutralizing Broth 2kg
Cat. no. C7373 CRITERION™ D/E Neutralizing Broth 10kg
Cat. no. C7374 CRITERION™ D/E Neutralizing Broth 50kg

INTENDED USE

Hardy Diagnostics CRITERION™ D/E Neutralizing Broth is an employed for neutralizing of antiseptics and disinfectants and detecting organisms remaining after treatment. This broth is especially suited for environmental sampling where neutralization of the chemical is important to determine its bactericidal activity.

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

D/E Neutralizing Broth, also known as Dey-Engley Neutralizing Broth, is capable of neutralizing a broad spectrum of antiseptic and disinfectant chemicals including ethanol, quaternary ammonium compounds, phenolics, iodine, chlorine preparations, mercurials, formaldehyde and glutaraldehyde. It can determine the bactericidal capability of disinfectants and therefore is well suited for environmental sampling (swab and contact plate methods).

Complete neutralization of disinfectants is important because disinfectant carryover can cause a false no-growth test result. D/E Neutralizing media effectively neutralizes the inhibitory effects of disinfectant carryover, allowing differentiation between bacteriostasis and the true bactericidal action of disinfectants.

FORMULA

Gram weight per liter: 42.4gm/L
Dextrose 10.0gm
Lecithin (Soy Bean) 7.0gm
Sodium Thiosulfate 6.0gm
Pancreatic Digest of Casein 5.0gm
Tween® 80 5.0gm
Yeast Extract 2.5gm
Sodium Bisulfite 2.5gm
Sodium Thioglycollate 1.0gm
Monopotassium Phosphate 0.10gm
Bromcresol Purple 0.02gm

Final pH 7.6 +/- 0.2 at 25ºC.

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

STORAGE AND SHELF LIFE

Store the sealed bottle(s) containing culture medium at 2-8ºC. Protect dehydrated culture media from moisture and light. The dehydrated culture media should be discarded if it is not homogenous, moist, and lumpy or if the color has changed from its original bluish-gray.

Store the prepared culture media at 2-8ºC.

PRECAUTIONS

METHOD OF PREPARATION

1. Suspend the 42.4gm of the dehydrated culture media in 1 liter of distilled or deionized water.

2. Heat to boiling and mix to dissolve completely to obtain an even suspension.

3. Dispense appropriate amount of the broth media into tubes.

4. Sterilize in the 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. U75.

LIMITATIONS

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
Bacillus subtilis
ATCC ® 6633
A 40-48hr 35°C Aerobic Growth; usually no color change
Escherichia coli
ATCC ® 25922
A 40-48hr 35°C Aerobic Growth; yellow color change
Pseudomonas aeruginosa
ATCC ® 9027
A 40-48hr 35°C Aerobic Growth; no color change
Salmonella enterica
ATCC ® 14028
A 40-48hr 35°C Aerobic Growth; yellow color change
Staphylococcus aureus
ATCC ® 6538
A 40-48hr 35°C Aerobic Growth; yellow color change

User Quality Control

PHYSICAL APPEARANCE

CRITERION™ D/E Neutralizing Broth powder should appear moist, lumpy, and bluish-gray in color. The prepared media should appear opaque, with an even suspension of particulates, and gray-purple to purple in color.

REFERENCES

1. FDA. 1995. Bacteriological Analytical Manual, 8th ed. FDA.

2 Marshall, R.T., ed. 1992. Standard Methods for the Examination of Dairy Products, 16th ed. APHA, Washington, D.C.

3 Vanderzant, C. and D.F. Splittstoesser, (ed.). 1992. Compendium of Methods for the Microbiological Examination of Foods, 3rd ed. APHA, Washington, D.C.

4 Greenberg, A.E., et al. (ed.). 1992. Standard Methods for the Examination of Water and Wastewater, 18th ed. APHA, Washington, D.C.

5. U.S. Pharmacopeia, 22nd rev. 1990. U.S. Pharmacopeial Convention, Rockville, MD.


ATCC is a registered trademark of the American Type Culture Collection.
Tween is a registered trademark of ICI Americas, Inc.

052316gr