LM-137 Agar Kit consists of LM-137 Agar Base (6906) and LM-137 Agar Supplement (6908). These two components are used with Egg Yolk Emulsion, 50% (7982) to prepare LM-137 Agar. LM-137 Agar is used for the presumptive enumeration of Listeria spp. using the ISO-GRID® and /or NEO-GRID® Membrane Filtration System in a laboratory setting. LM-137 Agar Kit is not intended for use in the diagnosis of disease or other conditions in humans.

LM-137 Agar was developed for the direct presumptive enumeration of Listeria spp., including Listeria monocytogenes, from food and environmental samples. This formula was designed to encourage rapid colony development of Listeria spp., while retarding or inhibiting growth of Gram-negative and Gram-positive competitors. LM-137 Agar is recommended for the direct presumptive enumeration of Listeria spp. and L. monocytogenes, from meats, poultry, dairy products, frozen eggs, and environmental samples using the using the ISO-GRID and /or NEO-GRID Membrane Filtration System method.


LM-137 Agar Base

Formula Liter
Enzymatic Digest of Casein 10 g
Yeast Extract 1 g
Sodium Pyruvate 10 g
Lithium Chloride 5 g
Magnesium Sulfate 7.4 g
Dextrose 1 g
Sodium Carbonate 1 g
Acriflavin 0.015 g
Liver Peptone 10 g
Agar 15 g

LM 137-Agar Supplement

Ingredients 20 mL Bottle
Triphenyltetrazolium Chloride 0.04 g
Polymyxin B Sulfate 0.02 g
Nalidixic Acid 0.08 g
Moxalactam, Disodium 0.01 g


Egg Yolk Emulsion, 100 mL

Aseptically add 50 mL of 50% Egg Yolk Emulsion

Formula may be adjusted and/or supplemented as required to meet performance specifications.


  1. Suspend 60.4 g of the medium in one liter of purified water.
  2. Heat with frequent agitation and boil for one minute to completely dissolve the medium.
  3. Autoclave at 121°C for 15 minutes.
  4. Cool to 45 – 50°C
  5. Aseptically add 50 mL of 50% Egg Yolk Emulsion (not containing tellurite) and 10 mL of rehydrated LM-137 Supplement.
  6. Mix thoroughly.
  7. Determine pH and aseptically adjust, if necessary, to pH 7.4 – 7.5.
  8. Pour into sterile Petri dishes.

Order Details

Product # Product Description
6906A LM-137 Agar, 500 g
6908E LM-137 Agar Supplement, 4 x 20 mL
6913A LM-137 Agar Kit, 500 g
7982 Egg Yolk Emulsion, 100 mL

Reference Material

6913 - LM-137 Agar, Product Information Sheet [English]

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