EC Medium, Modified with Novobiocin

EC Medium, Modified with Novobiocin is used for the selective enrichment of Escherichia coli O157:H7 in a laboratory setting. EC Medium, Modified with Novobiocin 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. EC Medium, Modified with Novobiocin is currently recommended by the U.S.D.A.


Formula Liter
Enzymatic Digest of Casein 20 g
Lactose 5 g
Sodium Chloride 5 g
Dipotassium Phosphate 4 g
Monopotassium Phosphate 1.5 g
Bile Salts 1.12 g
Novobiocin 0.020 g

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


  1. Dissolve 36.7 g of the medium in one liter of purified water.
  2. Autoclave at 121°C for 15 minutes.

Order Details

Product # Product Description
7700A EC Medium, Modified with Novobiocin, 500 g
7700T EC Medium, Modified with Novobiocin, 5 kg