Standard Methods Agar

Standard Methods Agar is used for the enumeration of bacteria in water, wastewater, food, and dairy products in a laboratory setting. Standard Methods Agar is not intended for use in the diagnosis of disease or other conditions in humans.. This formula conforms to American Public Health Association (APHA), and Association of Official Analytical Chemists (AOAC).

Standard Methods Agar was developed by Buchbinder, Baris, and Goldstein in 1953 at the request of the American Public Health Association. Results showed that a dehydrated milk-free medium containing 0.25% Yeast Extract, 0.5% Tryptone, 0.1% Dextrose, and 1.5% Agar per liter approximated the productivity of Tryptone Glucose Extract Agar with added milk. Buchbinder et al. recommended that a dehydrated culture medium be used in preparing the standard plate count medium rather than preparing the medium from ingredients. Standard Methods Agar as originally suggested by Buchbinder et al.

Standard Methods Agar is also referred to as Plate Count Agar and Tryptone Glucose Yeast Agar. This formula is specified in standard method procedures.


Formula Liter
Enzymatic Digest of Casein 5 g
Yeast Extract 2.5 g
Dextrose (Glucose) 1 g
Agar 15 g*

  *9 – 18 g according to gel strength
Final pH: 7.0 ± 0.2 at 25°C
Formula may be adjusted and/or supplemented as required to meet performance specifications.


  1. Suspend 23.5 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.

Order Details

Product # Product Description
7157A Standard Methods Agar, 500 g
7157T Standard Methods Agar, 5 kg