PHENOL RED BROTH

Technical Data # 2030a / 2010.08.31

Phenol Red Broth Base is used with carbohydrates for the differentiation of microorganisms on the basis of carbohydrate fermentation reactions.

 

FORMULA
in grams per litre purified filtered water

Enzymatic Digest of Casein.........10 g

Sodium Chloride...........................5 g

Phenol Red..................................0.018 g

Supplement

Desired Carbohydrates..............5 – 10 g

pH 7.4 ±0.2 at 25 ̊ C

This approximate formula may be adjusted and/or enriched to obtain best results.

PRECAUTIONS
This medium is for laboratory use only. Irritating to eyes, respiratory system, and skin.

STORAGE
Store prepared media at 2-30° C protected from direct light and moisture, in a dry place, in tightly-sealed containers.

SIGN OF DETERIORATION
Media should not be used if the expiry date has passed. Prepared media should not be used if there are signs of contamination or deterioration (shrinking, cracking, evaporation or discoloration). Do not use dehydrated media if it is caked.

DIRECTIONS

Suspend 15 g of the medium in 1000 mL of distilled purified water. Heat with frequent agitation and boil for one minute. If desired, add carbohydrates (5 – 10 g). Autoclave at 121 ̊ C for 15 minutes. Alternatively, filtered sterilized carbohydrate solutions may be added to the cooled sterilized broth.

PROCEDURE

1. Inoculate tubes with isolated colonies.

2. An inverted Durham tube, added to the broth medium prior to sterilization, is used to detect gas production.

3. Incubate at 35 ± 2 ̊ C for 18 – 48 hours with loose caps.

4. Examine tubes for growth, acid production and gas production (if Durham tube is used).

 

QUALITY CONTROL

Results at 35 ± 2̊ C and examined for growth after 18 - 48 hours incubation.

 

Microorganisms              ATCC

Approx. Inoculum (CFU)

Expected Results W/ Dextrose

Growth

Acid

Gas

Escherichia coli             25922

10 - 300

Good

+

+

Proteus vulgaris            13315

10 - 300

Good

-

-

Salmonella typhimurium                14028

10 - 300

Good

+

+

LIMITATIONS OF METHOD
This medium is only a part of the identification. Other tests may be required.

REFERENCES

1.       Isenberg, H. D. (ed.). 1992. Clinical microbiology procedures handbook. American Society for Microbiology, Washington, D.C.

2.       Murray, P. R., E. J. Baron, M. A. Pfaller, F. C. Tenover, and R. H. Yolken (eds.). Manual of clinical microbiology, 6th ed. American Society for Microbiology, Washington, D.C.

3.       Vera, H. D. 1950. Relation of peptones and other culture media ingredients to accuracy of fermentation tests. Am. J. Public Health. 40:1267.

4.       Bacteriological Analytical Manual. 1995. 8th ed. AOAC International, Gaithersburg, MD.

5.       Vanderzant, C., and D. F. Splittstoesser. 1992. Compendium of methods for the microbiological  examination of food. American Public Health Association, Washington, D.C.

6.       Association  of  Official  Analytical  Chemists.  1995.  Official  methods  of  analysis  of  AOAC  International.  AOAC  International, Arlington, VA.

7.       MacFaddin, J. F. 1985. Media for isolation-cultivation-identification-maintenance of medical bacteria. Williams & Wilkins, Baltimore, MD.

CATALOGUE NUMBER

Tube                        10pkg               2030