m-Enterococcus Agar

m-Enterococcus Agar is used for the selective isolation and enumeration of enterococci by membrane filtration in a laboratory setting. m-Enterococcus Agar is not intended for use in the diagnosis of disease or other conditions in humans.

m-Enterococcus Agar was first described by Slanetz et al. for the enumeration of enterococci by the membrane filtration technique. In 1957, Slanetz and Bartley modified this medium by adding triphenyltetrazolium chloride (TTC). Increased recovery and larger colonies were obtained by incubating the inoculated membranes on the agar surface instead of on pads saturated with liquid medium. The membrane filtration method is simple to perform, does not require confirmation, and permits a direct count of enterococci in 48 hours. m-Enterococcus Agar is also referred to as m-Azide Agar.

The presence of enterococci is a valuable bacterial indicator for determining the extend of fecal contamination of recreational surface waters. m-Enterococcus Agar is recommended for the detection of fecal streptococci using the membrane filtration technique for water testing. The food industry also has applications for testing enterococci using m-Enterococcus Agar.


Formula Liter
Enzymatic Digest of Casein 15 g
Enzymatic Digest of Soybean Meal 5 g
Yeast Extract 5 g
Dextrose 2 g
Dipotassium Phosphate 4 g
Sodium Azide 0.4 g
2,3,5-Triphenyl Tetrazolium Chloride 0.1 g
Agar 10 g

Final pH: 7.2 ± 0.2 at 25°C
Formula may be adjusted and/or supplemented as required to meet performance specifications.


  1. Suspend 42 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. DO NOT AUTOCLAVE. Cool to 45 – 50°C and dispense.

Order Details

Product # Product Description
7544A m-Enterococcus Agar, 500 g
7544T m-Enterococcus Agar, 5 kg