Yeast Extract Agar

Yeast Extract Agar is used for the enumeration of microorganisms in potable and freshwater samples in a laboratory setting. Yeast Extract Agar is not intended for use in the diagnosis of disease or other conditions in humans.

In nature, all water contains some impurities. As water flows in streams, sits in lakes, and filters through layers of soil and rock in the ground, it dissolves or absorbs the substances that it touches. Microbial pathogens are often found in water frequently as a result of fecal matter from sewage discharges, leaking septic tanks, or runoff from animal feedlots. Yeast Extract Agar is a rich, nutritious medium for the recovery of a wide range of bacteria, yeast, and molds. The combination of media ingredients and the appropriate incubation temperature of 36°C and 22°C allow the detection of a large number of microbial contaminants.

Yeast Extract Agar complies with the recommendation of ISO 6222 and the Swedish Standard SS 028171.


Formula Liter
Yeast Extract 3 g
Peptone 5 g
Agar 15 g

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


  1. Dissolve 23 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
7707A Yeast Extract Agar, 500 g
7707T Yeast Extract Agar, 5 kg