PURPLE BROTH WITH DURHAM TUBE

Cat. no. Y100 Purple Broth Base, 16x125mm Tube, 9ml 20 tubes/box
Cat. no. Y101 Purple Broth with Adonitol, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y102 Purple Broth with Arabinose, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y103 Purple Broth with Cellobiose, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y104 Purple Broth with Dextrose, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y105 Purple Broth with Dulcitol, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y106 Purple Broth with Inositol, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y108 Purple Broth with Lactose, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y109 Purple Broth with Maltose, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y110 Purple Broth with Mannitol, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y111 Purple Broth with Raffinose, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y112 Purple Broth with Rhamnose, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y113 Purple Broth with Salicin, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y114 Purple Broth with Sorbitol, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y115 Purple Broth with Sucrose, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y116 Purple Broth with Trehalose, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y117 Purple Broth with Xylose, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. Y119 Purple Broth with Mannose, 16x125mm Tube, 10ml 20 tubes/box

INTENDED USE

Hardy Diagnostics Purple Broth with Durham Tube is recommended for the determination of fermentation reactions of microorganisms, especially enteric bacilli and Enterococcus spp.

SUMMARY

The ability of bacteria to form organic compounds by metabolizing certain carbohydrates and related compounds is a widely used method for the identification of microorganisms.

Hardy Diagnostics Purple Broth consists of a sugar-free basal medium and a specific pH indicator. A 1% concentration of a specific carbohydrate is added in order to detect fermentation reactions. The 1% concentration is recommended to decrease the possibility of reversal reactions. Reversion occurs when the carbohydrate is depleted, thereby resulting in the masking of acid by-products by alkaline by-products of peptone degradation. The acid produced by carbohydrate breakdown causes a decrease in pH resulting in a color shift in the medium from blue-purple to yellow. Gas production is noted by the appearance of bubbles in the durham tube.

FORMULA

Ingredients per liter of deionized water:*

Purple Broth Base:

Dipeptone 10.0gm
Pancreatic Digest of Casein 6.0gm
Sodium Chloride 5.0gm
Beef Heart Infusion 2.0gm
Yeast Extract 2.0gm
Bromcresol Purple 20.0mg

Final pH 7.6 +/- 0.2 at 25ºC.

Purple Broth with 1% carbohydrate contains 10.0gm of a specific carbohydrate.

* 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, discoloration, contamination, or if the expiration date has passed. Product is light and temperature sensitive; protect from light, excessive heat, moisture, and freezing.

PRECAUTIONS

PROCEDURE

Specimen Collection: Specimen collection is not applicable since this medium is not intended for primary isolation from clinical specimens. As a general rule, 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. Consult listed references for information on specimen collection. (2-5)

Method of Use:

1. Allow medium to warm to room temperature prior to inoculation.

2. Inoculate the Purple Broth (carbohydrate of choice) with isolated colonies from an 18-24 hour pure culture of the organism. Note: A broth or saline suspension can be made to allow inoculation of a battery of carbohydrates.

3. Inoculate a control tube of Purple Broth Base (Cat. no. Y100) in parallel with the carbohydrate based media.

4. Incubate inoculated media aerobically at 35-37ºC. for 3-5 days.
Note: Increased incubation up to 30 days may be necessary for some microorganisms.

5. Observe daily for development of a yellow color in the medium.

INTERPRETATION OF RESULTS

The development of a yellow color in the medium is indicative of a positive carbohydrate fermentation reaction.

Lack of yellow color development is indicative of a negative carbohydrate fermentation reaction.

Gas formation is indicated by the appearance of gas bubbles in the durham tube.

LIMITATIONS

It may be necessary to invert the tube prior to inoculation if bubbles are trapped in the durham tube. Trapped bubbles that are not released may lead to false-positive results.

MATERIALS REQUIRED BUT NOT PROVIDED

Standard microbiological supplies and equipment such as loops, slides, staining supplies, other culture media, microscopes, incinerators, and incubators, as well as serological and biochemical reagents, are not provided.

QUALITY CONTROL

Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Purple Broth Base:
Escherichia coli
ATCC ® 25922
A 24hr 35°C Aerobic Growth; remains purple
Staphylococcus aureus
ATCC ® 25923
A 24hr 35°C Aerobic Growth; remains purple
Enterococcus faecalis
ATCC ® 29212
A 24hr 35°C Aerobic Growth; remains purple
Salmonella enterica
ATCC ® 14028
A 24hr 35°C Aerobic Growth; remains purple
Purple Broth with Lactose, Maltose, Mannitol, and Sorbitol:
Escherichia coli
ATCC ® 25922
A 24-48hr 35°C Aerobic Growth; turns yellow
Proteus mirabilis
ATCC ® 12453
A 24-48hr 35°C Aerobic Growth; remains purple
Purple Broth with Adonitol and Inositol:
Enterobacter aerogenes
ATCC ® 13048
A 24-48hr 35°C Aerobic Growth; turns yellow
Escherichia coli
ATCC ® 25922
A 24-48hr 35°C Aerobic Growth; remains purple
Purple Broth with Arabinose, Raffinose, and Rhamnose:
Enterobacter aerogenes
ATCC ® 13048
A 24-48hr 35°C Aerobic Growth; turns yellow
Serratia marcescens
ATCC ® 8100
A 24-48hr 35°C Aerobic Growth; remains purple
Purple Broth with Dextrose:
Escherichia coli
ATCC ® 25922
A 24-48hr 35°C Aerobic Growth; turns yellow
Branhamella ( Moraxella ) catarrhalis
ATCC ® 25240
A 24-48hr 35°C Aerobic Growth; remains purple
Purple Broth with Dulcitol:
Salmonella paratyphi
ATCC ® 9150
A 24-48hr 35°C Aerobic Growth; turns yellow
Serratia marcescens
ATCC ® 8100
A 24-48hr 35°C Aerobic Growth; remains purple
Purple Broth with Salicin and Sucrose:
Enterobacter aerogenes
ATCC ® 13048
A 24-48hr 35°C Aerobic Growth; turns yellow
Salmonella enterica
ATCC ® 14028
A 24-48hr 35°C Aerobic Growth; remains purple
Purple Broth with Cellobiose, Trehalose and Xylose:
Klebsiella pneumoniae
ATCC ® 13883
A 24-48hr 35°C Aerobic Growth; turns yellow
Morganella morganii
ATCC ® 25830
A 24-48hr 35°C Aerobic Growth; remains purple
Purple Broth with Mannose:
Klebsiella pneumoniae
ATCC ® 13883
A 24-48hr 35°C Aerobic Growth; turns yellow
Proteus mirabilis
ATCC ® 12453
A 24-48hr 35°C Aerobic Growth; remains purple

User Quality Control

PHYSICAL APPEARANCE

Purple Broth should appear clear and purple in color. Purple Broth with Inulin may have a slight to heavy precipitate.

E. coli growing in Purple Broth w/ Dextrose

Escherichia coli (ATCC ® 25922) growing in Purple Broth with Dextrose (Cat. no. Y104). The yellow color change is indicative a positive for dextrose fermentation. The bubble in the Durham tube indicates gas production. Incubated aerobically for 24 hours at 35ºC.

B. catarrhalis growing in Purple Broth w/ Dextrose

Moraxella (Branhamella) catarrhalis (ATCC ® 25420) growing in Purple Broth with Dextrose (Cat. no. Y104). No yellow color change is indicative as negative for dextrose fermentation. Incubated aerobically for 24 hours at 35ºC.

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. Hindler, J. 1996. June Seminar. What Can We Do About Vancomycin-Resistant Enterococci (VRE) in Southern California, UCLA Medical Center, Los Angeles, CA.


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

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