m ENDO LES AGAR

Technical Data #1250a / 2013.06.27

m-Endo Les Agar is a selective solid medium for detection and
enumeration of fecal coliforms organisms by the membrane filter
technique. Desoxycholate and lauryl sulfate inhibit gram-positive bacteria. Basic Fuchsine is the pH indicator.

 


 

FORMULA
in grams per liter purified filtered water

Casein Peptone

8,7

Yeast Extract

3,7

Meat Peptone

3,7

Lactose

9,4

Sodium Chloride

3,7

Potassium Phosphate, monobasic

1,0

Potassium Phosphate, dibasic

3,3

Sodium Deoxycholate

0,1

Sodium Lauryl Sulfate

0,05

Sodium Sulfite

1,6

Basic Fuchsine

0,8

Agar

14,0

pH 7,2 +/- 0,2 25 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 (shrinking, cracking, evaporation or discoloration). Do not use dehydrated media if it is caked.


DIRECTIONS
Suspend 50 g of dehydrated media in 1000 ml of purified filtered water containing 20 ml of ethanol. Heat with frequent agitation and boil for one minute. DO NOT AUTOCLAVE. Cool to 45-50 C. Mix gently and dispense into sterile Petri dishes.


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

  1. Place a membrane filter pad in the lid and saturate with 2 ml of Sodium Lauryl Sulfate Broth (2844). Remove any excess liquid.
  2. Apply the membrane filter used to collect the water sample, on the surface of the pad. Avoid air bubbles.
  3. Incubate at 35 C for 2 hours.
  4. Transfer the membrane filter from the pad on the agar surface. Avoid air bubbles.
  5. Incubate at 35C for 20-22 hours.


QUALITY CONTROL

Results after 24 hrs at 35C

Organisms

ATCC

Growth

Colour

Escherichia coli

25922

+

red/metallic sheen

Enterobacter aerogenes

13048

+

red/metallic sheen

Salmonella typhimurium

14028

-

colorless

Staphylococcus aureus

25923

- or partial

 


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


REFERENCES

  1. McCarthy .J.A., J.E. Delaney, R.J. Grasso 1961 Measuring coliforms in water. Water Sewage Works. 108:238.
  2. Mac Faddin, Jean F., 1985 Media for Isolation-Cultivation-Identification-Maintenance of Medical Bacteria. Vol.1. Baltimore, MD.: Williams & Wilkins.
  3. Standard Methods for Examination of Water and Wastewater 1989 17th ed. APHA Washington D.C.


CATALOGUE NUMBERS

Dehydrated media 500 grams QB-39-2690
Prepared media    
Plates,100x15 mm 10/pkg 1681
Mono-Plates, 100x15 mm 10/pkg 1681M
Plates, 60x15 mm 10/pkg 1250
Plates, 150x15 mm 5/pkg 1395
Mueller Hinton Broth    
Tubes, 16x125 mm 10/pkg  
Sodium Lauryl Sulfate Broth    
Tubes, 20x125 mm, 10 ml 10/pkg 2844

 


 

 

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