Product number: 7506

EC Medium, Modified is used with novobiocin for the selective pre-enrichment of Escherichia coli O157:H7 in a laboratory setting. EC Medium, Modified is not intended for use in the diagnosis of disease or other conditions in humans.

EC Medium was developed by Hajna and Perry in an effort to improve the methods for the detection of the coliform group and E. coli. This medium consists of a buffered lactose broth with the addition of 0.15% Bile Salts Mixture. Growth of spore-forming bacteria and fecal streptococci were inhibited by the bile salts. EC Medium, Modified with the addition of novobiocin was first described by Okrend and Rose. Okrend and Rose modified EC Medium by reducing the Bile Salts Mixture concentration to 1.12% and adding 20 mg/L of sodium novobiocin. Okrend and Rose et al. reported this formulation, which they called Modified EC & Novobiocin (mEC&N), was beneficial in the enrichment and detection of E. coli O157:H7 from meats and poultry, and is currently recommended by the U.S.D.A.


Formula Liter
Enzymatic Digest of Casein 20 g
Lactose 5 g
Bile Salts Mixture 1.12 g
Dipotassium Phosphate 4 g
Monopotassium Phosphate 1.5 g
Sodium Chloride 5 g

Final pH: 6.9 ± 0.2 at 25°C
Formula may be adjusted and/or supplemented as required to meet performance specifications.

Novobiocin Supplement, 10 mL

Novobiocin, 20 mg


  1. Dissolve 36.6 g of the medium in one liter of purified water.
  2. Mix thoroughly.
  3. Autoclave at 121°C for 15 minutes.
  4. Cool to room temperature and add 10 mL of the Novobiocin Supplement (# 7985).
  5. Dispense aseptically into sterile tubes containing an inverted fermentation Durham tube.

Order Details

Product # Product Description
7506A EC Medium, Modified, 500 g
7985 Novobiocin Supplement, 10 x 10 mL

Reference Material

7506 - EC Medium, Modified, Product Information Sheet [English] [Portuguese]

For additional information or questions about product SDS documents, please contact Neogen at

Please check with your local representative for availability of these products within your region.