ESCULIN AGAR

Technical Data #2418a / 2013.10.11

Esculin Agar is a solid test medium used for microorganisms identification by their ability to hydrolyze the glycoside esculin to esculetin. Bacteroides sp may be differentiated as well as Pseudomonas sp.

 


 

FORMULA
in grams per liter purified filtered water

Gelatin Peptone

5,0

Beef Extract

3,0

Esculin

1,0

Ferric Citrate

0,5

Agar

15,0

pH 7,0 +/- 0,2 at 25º C

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


PRECAUTIONS
This medium is for laboratory use only.


STORAGE
Store prepared media at 2-8º C protected from direct light.


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).


DIRECTIONS
Suspend 24.5 g of dehydrated media in 1000 ml of purified filtered water. Heat with frequent agitation and boil for one minute. Sterilize at 121º C for 15 minutes. Cool to 45-50º C. Mix gently and dispense into sterile Petri dishes or sterile culture tubes.


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

  1. Inoculate plates or tubes with 2-3 similar colonies to be
  2. Incubate at 35º C for 24-48 hours.
  3. Examine for blacknening of the medium.


QUALITY CONTROL

Results after 24 hrs at 35ºC

Organisms

ATCC

Esculin Hydrolyze

Pseudomonas aeruginosa

27853

-

Burkholderia cepacia

25416

+

Klebsiella pneumoniae

13883

+

Escherichia coli

25922

-

Bacteroides fragilis

25285

+


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


REFERENCES

  1. Dowell, V.R. Jr., G.L. Lombard 1977 Presumptive identification of anaerobic nonsporeforming gram-negative bacilli. Center for Disease Control Atlanta.
  2. Lennette, E.H., Ballows, A., Hausler, W.J.Jr., and Shadomy, H.J. Manual of Clinical Microbiology. 4th ed. 1985 Washington D.C.: American society for Microbiology.
  3. Mac Faddin, Jean F., Media for Isolation-Cultivation-Identification-Maintenance of Medical Bacteria Vol.1 1985 Baltimore, MD. Williams & Wilkins.
  4. Washington, J.A. Laboratory Procedures in Clinical Microbiology 1981. Springer-Verlag, New York.


CATALOGUE NUMBERS

Dehydrated media 500 g QB-39-2190
     
Prepared media    
Tubes, 16x125 mm, 5 ml 10/pkg 2418
Tubes, 13x100mm, 2ml 10/pkg 2074

 


 

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