EnzyChrom™ Urea Assay Kit III

Protocol SDS

Application

• For quantitative enzymatic determination of urea.

Key Features

• Fast and sensitive. Linear detection range (20 µL sample): 50 to 1000 µM urea in 96-well plate assay.
• Convenient. The procedure involves adding a single working reagent, and reading the absorbance after 30 minutes. Room temperature assay. No 37°C heater is needed.
• High-throughput. Homogeneous “mix-incubate-measure” type assay.Can be readily automated as a high-throughput 96-well plate assay for thousands of samples per day.

Method

• OD340nm

Samples

• Urea in biological samples (e.g. plasma, serum, urine, bronchoalveolar lavage (BAL)) and food/beverage samples (e.g. milk)

Species

• All

Procedure

• 30 min

Size

• 100 tests

Detection Limit

• 50 µM

Shelf Life

• 6 months

More Details

UREA, the major end product of protein catabolism in animals, is primarily produced in the liver and secreted by the kidneys. It is the primary vehicle for removal of toxic ammonia from the body. Urea determination is very useful for medical clinicians to assess kidney function of patients. In general, increased urea levels are associated with nephritis, renal ischemia, urinary tract obstruction, and certain extrarenal diseases (e.g. congestive heart failure, liver diseases, and diabetes). Decreased levels often indicate acute hepatic insufficiency, but may also result from over vigorous parenteral fluid therapy. Simple, direct and automation-ready procedures for measuring urea or blood urea nitrogen (BUN) are popular in research and drug discovery.BioAssay Systems urea assay is designed to directly measure urea in biological samples. In this assay, urease converts urea to ammonia and carbon dioxide. NADH is then converted to NAD+ in the presence of ammonia, α-ketoglutarate, and glutamate dehydrogenase. The decrease in optical density at 340 nm is directly proportional to the urea concentration in the sample.

How do I store the kit?

This kit is shipped on ice. Upon receiving, please store the kit at -20°C. Urease can be stored at -20°C to 4°C.

Can I store unused reagents for future use?

Yes, unused reagents can be stored according to the assay protocol. Repeated freeze/thaw cycles of reagents should be avoided. The dried NADH Reagent is stable for 3 weeks after reconstitution.

Does glutamate in the sample interfere with the assay?

High glutamate concentrations (> 2 mM) will interfere with the assay. For example a typical concentration of glutamate in cell culture medium is ~0.15 mM.

I do not see any color change in my wells. Is the assay not working?

This assay measures the decrease in OD at 340 nm and the color change is not visible to the naked eye.

Duarte, N. T. et al (2020). Prevalence of sublingual varices in patients with cirrhosis and the correlation with nitrogen compounds. Oral surgery, oral medicine, oral pathology and oral radiology, 129(1), 39-44. Assay: urea in human saliva and blood.

To find more recent publications, please click here.

If you or your labs do not have the equipment or scientists necessary to run this assay, BioAssay Systems can perform the service for you.

– Fast turnaround
– Quality data
– Low cost

Please email or call 1-510-782-9988 x 2 to discuss your projects.