Aug 10, 2022 · Urea Agar was developed by Christensen in 1946 for the differentiation of enteric bacilli. The urease test is used to determine the ability of an organism to split urea, through the production of the enzyme urease.

Urea Agar is a lightly buffered medium containing urea and phenol red, a pH indicator. When organisms utilize urea, ammonia is formed which turns the medium alkaline. Phenol red changes the medium color from pale-yellow to pink-red in an alkaline environment.

Urease is a constitutively expressed enzyme that hydrolyzes urea to carbon dioxide and ammonia. Many organisms especially those that infect the urinary tract, have a urease enzyme that is able to split urea in the presence of water to release ammonia and carbon dioxide.

Jan 23, 2022 · The urea agar base used for the testing of urease activity is named Christensen Urea Agar after him. During the test, the organisms utilize urea as the sole source of nitrogen, producing a sufficient amount of ammonia to overcome the buffering capacity of the medium.

Urea Agar contains urea and phenol red as the pH indicator. Organisms capable of hydrolyzing urea form ammonia as a by product, thus turning the medium alkaline. The pH indicator turns from pale yellow to pink-red in color in these conditions.

Urea agar (Christensen’s urea agar) has a reduced buffer content and contains peptones and glucose. This medium supports the growth of many enterobacteria allowing for the observation of urease activity. Two media types are commonly used to detect urease activity.

Urea Agar is used to detect rapid urease activity of the Proteae and non-rapid urease activity of some Enterobacteriaceae. Urea Agar is a lightly buffered medium that contains urea and phenol red, a pH indicator.

Urea Agar Base with the addition of Urea is recommended for the detection of urease production, particularly by members of the genus Proteus. Store prepared media below 8°C, protected from direct light. Store dehydrated powder in a dry place in tightly-sealed. containers at 2-25°C. Light pink colored, homogenous, free flowing powder.

Rapid automated method for screening of enteric pathogens from stool specimens.

Urea Agar Base may be used as a screening medium (along with Triple Sugar Iron Agar) for the selection of Salmonella and Shigella cultures for serologic classification. Urea Agar Base is also used to detect production of urease by yeast.