G.N. (GRAM NEGATIVE) HAJNA BROTH

Technical Data #2798a / 2013.11.01

GN Broth is a selective enrichment medium used for cultivation of Gram negative from various sources. Mannitol enhances Salmonella and Shigella recovery. Sodium citrate and sodium deoxycholate are the inhibitors.

 


 

FORMULA
in grams per liter purified filtered water

Casein Peptone

10,0

Meat Peptone

10,0

Dextrose

1,0

Mannitol

2,0

Sodium Citrate

5,0

Sodium Deoxycholate

0,5

Potassium Phosphate, dibasic

4,0

Potassium Phosphate, monobasic

1,5

Sodium Chloride

5,0

pH 7,0 +/- 0,2 à 25º C

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


PRECAUTIONS
This medium is for IN VITRO diagnostic use only.


STORAGE
Store prepared media at 2-8° C protected from direct light and dehydrated powder, in a dry place, in tightly-sealed containers at 2-25° C.


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, evaporation or discoloration. Do not use dehydrated media if it is caked.


DIRECTIONS
Suspend 39 g of dehydrated media in 1000 ml of purified filtered water. Mix gently and dispense into culture tubes. Sterilize at 118° C for 15 minutes.


PROCEDURE
Prior to inoculate, the prepared media should be brought to room temperature.

  1. Inoculate tubes with specimens.
  2. Incubate at 35° C for 24 hours with loosened caps.
  3. Subculture on selective media SS (#1127) or Hektoen (#1882) for isolation after only 6-8 hours of incubation or after 24 hours.


QUALITY CONTROL

Results after 24 hrs at 35ºC

Organisms

ATCC

GROWTH

Salmonella typhimurium

14028

+

Shigella sonnei

9290

+

Escherichia coli

25922

+

Staphylococcus aureus

25923

-


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


REFERENCES

  1. Hajna, A.A., 1955 A new specimen preservative for Gram negative organisms of the intestinal group. Public Health Lab 13:83
  2. Lennette, E.H., Ballows, A., Hausler, W.J. Jr, and Shadomy, H.J. 1985 Manual of Clinical Microbiology, 4th ed., Washington, DC. American Society for Microbiology.
  3. Mac Faddin, Jean, F. 1985 Identification-Cultivation-Maintenance of Medical Bacteria Vol.1, Baltimore, MD, Williams & Wilkins
  4. N.C.C.L.S. 1996 Quality Assurance for Commercially Prepared Microbiological Culture Media Approved Standard.


CATALOGUE NUMBERS

Dehydrated media 500 grams QB-39-1915
     
Prepared media    
Tubes, 16x125 mm, 10 ml 10/pkg 2798
  100/pkg 2798-H

 


 

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