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QuantiChrom™ Urea Assay Kit II


  • For quantitative enzymatic determination of urea.

Key Features

  • Fast and sensitive. Linear detection range (20 µL sample): 1 mg/mL (0.17 mM) to 100 mg/mL (17 mM) urea in 96-well plate assay.
  • Convenient. The procedure involves adding a single working reagent, and reading the absorbance after 5 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.


  • OD557nm


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


  • All


  • 5 min


  • 100 tests

Detection Limit

  • 1 mg/mL (0.17 mM)

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.BioAssay Systems colorimetric urea (BUN) assay is based on urease catalyzed conversion of urea to ammonium and carbon dioxide. The pH of the reaction medium is monitored by a chromogen and the intensity of the reaction product at 557 nm is directly proportional to the urea concentration in the sample.

How do I store the kit?

This kit is shipped at room temperature. Upon receiving, please store the Reagent and Standard in the refrigerator (4°C) and the Urease at -20°C to 4°C. For long term storage, keep the standard at -20°C.

There is a standard curve shown on the datasheet, why do I not construct one?

Yes, there is a standard curve in the datasheet; we include this to show the linear detection range of the kit for quantifying urea. Due to interference, an internal standard must be run for most samples. The datasheet has detailed information on how to perform this and calculate urea concentration from it.

I would like to construct a standard curve, how can I go about that?

If you wish to construct a standard curve, you may dilute the urea standard in dH2O and follow the instructions from question 4 below.

How can I detect urea in urine samples?

Please refer to our DUR2-100 Urine Detection Protocol.

Can I store unused reagents for future use?

Yes, unused reagents can be stored according to the assay protocol.

I am not obtaining consistent data, what could be the problem?

This assay is pH dependent; therefore, temperature can affect the results. Be sure to equilibrate all components to room temperature before each assay.

Tokunaga, A.,et al (2020). Effect of chronic kidney disease on hepatic clearance of drugs in rats. Biological & Pharmaceutical Bulletin, 43(9), 1324-1330. Assay: Urea in rat serum.

Yang, W.,et al (2017). Epigallocatechin-3-gallate decreases the transport and metabolism of simvastatin in rats. Xenobiotica; the Fate of Foreign Compounds in Biological Systems, 47(1), 86-92. Assay: Urea in rat plasma.

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 request assay service.


For orders of 10 or more kits, please call +1-510-782-9988×1 or email us for best pricing and/or bulk order.

Orders are shipped the same day if placed by 2pm PST
Shipping: RT
Carrier: Fedex
Delivery: 1-2 days (US), 3-6 days (Intl)
Storage: -20°C upon receipt

Why BioAssay Systems?

Technical support provided by the very scientists that develop the assays.

Products are extensively tested and validated prior to release so researchers need little-to-no time for assay optimization.

Because we develop and manufacture the products, our prices are lower than competitors on the market

With over 200 different products, acquire all your assay kit needs in one order.

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