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Bacteriological Analytical Manual (BAM) Media M40: Christensen's Urea Agar

January 2001 


Peptone1 g
NaCl5 g
Dextrose1 g
KH2PO42 g
Phenol red
(6 ml of 1:500 solution)
0.012 g
Agar15 g
Distilled water900 ml


Dissolve all ingredients except urea in 900 ml water (basal medium).


For halophilic Vibrio spp., add extra 15 g NaCl (final NaCl concentration, 2%).


Autoclave 15 min at 121°C. Cool to 50-55°C.


Urea concentrate

Urea20 g
Distilled water100 ml


Dissolve urea in 100 ml water.


Filter-sterilize; add aseptically to cooled basal medium. Mix. Final pH, 6.8 ± 0.1. Dispense to sterile tubes or petri dishes. Slant tubes for 2 cm butt and 3 cm slant.

Original Source: Bacteriological Analytical Manual, 8th Edition, Revision A, 1998.