Urease (UE) is widely distributed in the seeds of plants, also in the blood and urine of animals. Some
microorganisms can also secrete urease. UE can hydrolyze urea to ammonia and carbonic acid, which
plays a key role in urea transformation. The UE activity can be determined by calculating the content of
NH3-N with indophenol blue colorimetry.
Reagents and Equipment Required but Not Provided:
Spectrophotometer/ microplate reader, micro glass cuvette/ 96 well flat-bottom plate, constant
temperature water bath, low temperature centrifuge, balance, mortar/homogenizer.
Sample preparation:
I. Bacteria or cells: Number of cells / bacteria (104): volume of extract solution (mL) is 500-1000:1.
Suggested 5 million with 1mL of extract solution. Splitting bacteria or cells with ultrasonication (ice
bath, power 300W, work time 3s， interval 7s， repeat 3 min), centrifuge at 12000g and 4℃ for
15min, supernatant on ice is used for test.
II. Tissue: Mass (g): extraction volume (mL) is 1:5-10. Add 1 ml of extract solution into 0.1g of tissue,
fully grinding on ice. centrifuge at 12000g and 4℃ for 15min, supernatant on ice is used for test
III. Serum/ plasma: Detect directly.
