s Cell BioSciences


Urea Agar Base

Urea Agar Base is used with agar for the differentiation of microorganisms on the basis of urease production in a laboratory setting. Urea Agar Base is not intended for use in the diagnosis of disease or other conditions in humans.

Christensen devised a urea agar medium containing peptone and dextrose that had a reduced buffer content. The medium supported a vigorous growth of many Gram-negative, enteric bacilli and readily permitted observation of urease production. Urea Agar Base may be used as a screening medium (along with Triple Sugar Iron Agar) for the selection of Salmonellaand Shigella cultures for serologic classification. Urea Agar Base is used to detect production of urease by yeast. Urease production is an important differential test in microbiology and outlined in standard methods.


Formula Liter
Enzymatic Digest of Gelatin 1 g
Dextrose 1 g
Sodium Chloride 5 g
Monopotassium Phosphate 2 g
Urea 20 g
Phenol Red 0.012 g

Final pH: 6.8 ± 0.2 at 25°C
Formula may be adjusted and/or supplemented as required to meet performance specifications.


Agar, Bacteriological 15 g


  1. Suspend 29 g of the medium in 100 mL of purified water until dissolved completely. Filter sterilize.
  2. Suspend 15 g of agar in 900 mL of purified water.
  3. Heat with frequent agitation and boil for one minute to completely dissolve the medium.
  4. Autoclave at 121°C for 15 minutes.
  5. Cool sterilized agar to 45 – 50°C and aseptically add the sterile Urea Agar Base.
  6. Mix thoroughly and dispense into sterile tubes. Place tubes in a slanted position.

Order Details

Product # Product Description
7226A Urea Agar Base, 500 g
7226T Urea Agar Base, 5 kg
7178A Agar Bacteriological, 500 g