Urease Test The urease test is used to determine the ability of an organism to split urea, through the production of the enzyme urease. Principle Urea is the product of decarboxylation of amino acids . Hydrolysis of urea produces ammonia and CO2 . The formation of ammonia alkalinizes the medium, and the pH shift is detected by the color change of phenol red from light orange at pH 6.8 to magenta (pink) at pH 8.1. Rapid urease-positive organisms turn the entire medium pink within 24 hours. Weakly positive organisms may take several days, and negative organisms produce no color change or yellow as a result of acid production . Uses 1. This test is used to differentiate organisms based on their ability to hydrolyze urea with the enzyme urease. 2. This test can be used as part of the identification of several genera and species of Enterobacteriaceae, including Proteus, Klebsiella ,
Comments