Application

• For quantitative determination of urea and evaluation of drug effects on urea metabolism.

Key Features

• Sensitive and accurate. Use 5 µL samples. Linear detection range 0.08 mg/dL (13 µM) to 100 mg/dL (17 mM) urea in a 96-well plate assay.
• Simple and high-throughput. The procedure involves the addition of a single working reagent and incubation for 20 min. Can be readily automated as a high-throughput assay for thousands of samples per day.
• Improved reagent stability and versatility. The optimized formulation has greatly enhanced the reagent and signal stability. Cuvet or 96-well plate assay.
• Low interference in biological samples. No pretreatments are needed. Assays can be directly performed on raw biological samples i.e., in the presence of lipids and protein.

Method

• OD520nm (Chemical)

Samples

• Serum, plasma, urine, milk, cell/tissue culture, bronchoalveolar lavage (BAL), food, beverage, and environment

Species

• All

Procedure

• 30 min

Size

• 100 tests

Detection Limit

• 0.08 mg/dL (13 µM)

Shelf Life

• 12 months

More Details

What is the principle of the urea assay?

The reaction proceeds with two steps and is based on a method developed by Jung et al. The first step is the condensation reaction of ortho-phthaldialdedyde with urea. The second step involves the rapid reaction with primaquine diphosphate that undergoes rearrangement to yield an intensely colored product.

I wonder if your urea assay kit could measure urea concentrations in dairy cow urine? Total nitrogen runs 240 grams per dL. Urea runs 50-70% of this amount, depending on ration components.

Yes, you can measure urea in cow urine with our urea assay. We would suggest that you dilute the urine 10-fold in water prior to the assay. This will give a final concentration of 12 to 17 mg/dL and is within the linear detection range of the assay (0 to 50 mg/dL).

Is it normal that plasma samples form precipitates after the addition of working reagent?

Some plasma samples will form precipitates after the addition of the working reagent. If this is the case, we recommend to perform the reaction in a microtube centrifuge at maximum speed for five minutes and use the clear supernatant for the measurement.

I was curious if ammonia/ammonium interferes with your urea assay (DIUR-500)? I am looking for an assay to measure in vitro urea conversion from ammonium chloride within culturing media by hepatocytes, and am wondering if this assay should be applicable for this goal.

Ammonium does not interfere with the assay. Unlike the other urea assays which measure ammonium after enzymatic conversion of urea to ammonium, this assay measures urea directly. Thus you can use our urea assay for your experiment.

Does peroxide interfere with the assay?

Yes. High concentrations of hydrogen peroxide (1%) completely block color development. We have not tested lower concentrations.

Does ethanol interfere with the assay?

No. Up to 25% ethanol in the sample does not interfere with the reaction.

I am planning to measure urea from culture supernatant. My medium contains phenol red, so I am wondering how to correct for the background by phenol red?

You should measure the OD at 430 nm, because the background by phenol red will be much lower than at 520 nm. Generally, I would recommend to run the standard in phenol red containing medium and use medium as blank instead of water.

Andres-Hernando, A., et al (2019). Obesity causes renal mitochondrial dysfunction and energy imbalance and accelerates chronic kidney disease in mice. APSselect, 6(10), F941-F948. Assay: Urea in mice blood.

Chalmers, S. A., et al (2019). NF-kB signaling in myeloid cells mediates the pathogenesis of immune-mediated nephritis. Journal of Autoimmunity, 98, 33-43. Assay: Urea in mice terminal serum.

Vorland, C. J., et al (2019). Effect of ovariectomy on the progression of chronic kidney disease-mineral bone disorder (Ckd-mbd) in female Cy/+ rats. Scientific Reports, 9(1), 7936. Assay: Urea in female rats plasma.

Brown, C. N., et al (2020). The effect of MEK1/2 inhibitors on cisplatin-induced acute kidney injury (Aki) and cancer growth in mice. Cellular Signalling, 71, 109605. Assay: Urea in male C57BL/6 J mice blood.

Spada, M., et al (2020). Intrahepatic administration of human liver stem cells in infants with inherited neonatal-onset hyperammonemia: A phase i study. Stem Cell Reviews and Reports, 16(1), 186-197. Assay: Urea in human liver stem-like cells.

Kristiansson, A., et al (2021). 177lu-psma-617 therapy in mice, with or without the antioxidant α1-microglobulin (A1m), including kidney damage assessment using 99mtc-mag3 imaging. Biomolecules, 11(2). Assay: Urea in mice serum/plasma.

Patil, B. R., et al (2020). Design of a novel theranostic nanomedicine (Iii): Synthesis and physicochemical properties of tumor-targeting cisplatin conjugated to a hydrophilic polyphosphazene. International Journal of Nanomedicine, 15, 981-990. Assay: Urea in mice plasma.

Lai, L., et al (2021) Bovine serum albumin aggravates macrophage M1 activation and kidney injury in heterozygous Klothodeficient mice via the gut microbiota-immune axis. International Journal of Biological Sciences 17(3): 742-755 Assay: Urea in mice plasma.

Liu, X., et al (2019). Caspase recruitment domain family member 10 regulates carbamoyl phosphate synthase 1 and promotes cancer growth in bladder cancer cells. Journal of Cellular and Molecular Medicine, 23(12), 8128-8138. Assay: Urea in human bladder cancer cells.

Akakpo, J. Y., et al (2020). 4-methylpyrazole protects against acetaminophen-induced acute kidney injury. Toxicology and Applied Pharmacology, 409, 115317. Assay: Urea in mice Kidney Tissue.

Wang, J. (2020). Protective effect of ethyl acetate fraction from Semen sojae germinatum, the processed sprout of Chinese black soybean, on rat experimental osteoarthritis. BMC Complementary Medicine and Therapies, 20(1), 117. Assay: Urea in rats Synovial fluid lavage.

Imtiazul, I. M., et al. (2019). Change of surfactant protein D and A after renal ischemia reperfusion injury. PloS One, 14(12), e0227097. Assay: Urea in mice blood.

Swallow, E. A., et al. (2019). Skeletal levels of bisphosphonate in the setting of chronic kidney disease are independent of remodeling rate and lower with fractionated dosing. Bone, 127, 419-426. Assay: Urea in male Cy/+ Han:SPRD rat blood.

Paraskevopoulou, V., et al. (2020). Notch controls urothelial integrity in the mouse bladder. JCI Insight, 5(3). Assay: Urea in WT mice serum.

Balasubbramanian, D., et al. (2020). Kidney-specific lymphangiogenesis increases sodium excretion and lowers blood pressure in mice. Journal of Hypertension, 38(5), 874-885. Assay: Urea in mice urine.

Lovisa, S., et al. (2020). Endothelial-to-mesenchymal transition compromises vascular integrity to induce Myc-mediated metabolic reprogramming in kidney fibrosis. Science Signaling, 13(635). Assay: Urea in mice serum.

Lee, S.-O., et al. (2021). Renal protective effect of beluga lentil pretreatment for ischemia-reperfusion injury. BioMed Research International, 2021, 6890679. Assay: Urea in mouse serum.

Trotta, R. J., et al. (2021). Influence of ractopamine hydrochloride supplementation on pancreatic digestive enzyme activity in finishing steers. Canadian Journal of Animal Science, 101(1), 191-195. Assay: Urea in finishing steer serum.

Bhogal, R.H., et al. (2011). Isolation of primary human hepatocytes from normal and diseased liver tissue: a one hundred liver experience. PLoS One 6(3):e18222. Assay: Urea in human primary hepatocytes.

Chavez Valdez, R., et al. (2011). Correlation between serum caffeine levels and changes in cytokine profile in a cohort of preterm infants. J Pediatr 158(1):57-64, 64 e1. Assay: Urea in human tracheal aspirates.

Gatti, S., et al. (2011). Microvesicles derived from human adult mesenchymal stem cells protect against ischaemia-reperfusion-induced acute and chronic kidney injury. Nephrol Dial Transplant 26(5):1474-83. Assay: Urea in rat serum.

Giguere, S., et al. (2011). Disposition of gamithromycin in plasma, pulmonary epithelial lining fluid, bronchoalveolar cells, and lung tissue in cattle. Am J Vet Res 72(3):326-30. Assay: Urea in cattle bronchoalveolar lavage fluid.

Pauwelyn, K., et al. (2011). Culture of mouse Embryonic Stem Cells with Serum but without Exogenous Growth Factors Is Sufficient to Generate Functional Hepatocyte-Like Cells. PLoS One 6(8):e23096. Assay: Urea in mouse cells.

Radunz, A.E., et al. (2011). Winter-feeding systems for gestating sheep I. Effects on pre- and postpartum ewe performance and lamb progeny preweaning performance. J Anim Sci 89(2):467-77. Assay: Urea in sheep plasma.

Sekiya S, Suzuki A (2011). Direct conversion of mouse fibroblasts to hepatocyte-like cells by defined factors. Nature 475(7356):390-3. Assay: Urea in mouse hepatocyte cultures.

Benjamin, J.T., et al. (2010). NF-kappaB activation limits airway branching through inhibition of Sp1-mediated fibroblast growth factor-10 expression. J Immunol 185(8):4896-903. Assay: Urea in human tracheal fluid.

Dennen, P., et al. (2010). Urine interleukin-6 is an early biomarker of acute kidney injury in children undergoing cardiac surgery. Crit Care 14(5):R181. Assay: Urea in mouse blood.

Hauser, P.V., et al. (2010). Stem cells derived from human amniotic fluid contribute to acute kidney injury recovery. Am J Pathol 177(4):2011-21. Assay: Urea in mouse serum.

Miller, J.D., et al. (2010). Chorioamnionitis stimulates angiogenesis in saccular stage fetal lungs via CC chemokines. Am J Physiol Lung Cell Mol Physiol 298(5):L637-45. Assay: Urea in human tracheal aspirates.

Park, Y., et al. (2010). Expansion and hepatic differentiation of rat multipotent adult progenitor cells in microcarrier suspension culture. J Biotechnol 150(1):131-9. Assay: Urea in rat multipotent adult progenitor cells.

Ponda, M.P., et al. (2010). Methylamine clearance by haemodialysis is low. Nephrol Dial Transplant 25(5):1608-13. Assay: Urea in human plasma.

Roelandt P et al (2010). Differentiation of rat multipotent adult progenitor cells to functional hepatocyte-like cells by mimicking embryonic liver development. Nat Protoc. 5(7):1324-36. Assay: Urea in human cell media.

Roelandt, P., et al. (2010). human embryonic and rat adult stem cells with primitive endoderm-like phenotype can be fated to definitive endoderm, and finally hepatocyte-like cells. PLoS One 5(8):e12101. Assay: Urea in human cells.

Sahan-Firat, S., et al. (2010). 2,3′,4,5′-Tetramethoxystilbene prevents deoxycorticosterone-salt-induced hypertension: contribution of cytochrome P-450 1B1. Am J Physiol Heart Circ Physiol 299(6):H1891-901. Assay: Urea in rat urine.

Watanabe, M., et al (2010). AAVrh.10-mediated genetic delivery of bevacizumab to the pleura to provide local anti-VEGF to suppress growth of metastatic lung tumors. Gene Ther 17(8):1042-51. Assay: Urea in mouse bronchoalveolar lavage fluid.

Devalaraja-Narashimha, K., et al. (2009). Cyclophilin D gene ablation protects mice from ischemic renal injury. Am J Physiol Renal Physiol 297(3):F749-59. Assay: Urea in mouse blood.

Pesce, J.T., et al. (2009). Arginase-1-expressing macrophages suppress Th2 cytokine-driven inflammation and fibrosis. PLoS Pathog 5(4):e1000371. Assay: Urea in mouse macrophages.

Salerno, S., et al. (2009). Improved functions of human hepatocytes on NH3 plasma-grafted PEEK-WC-PU membranes. Biomaterials 30(26):4348-56. Assay: Urea in human primary hepatocytes.

Wang, A., et al. (2009). CXCR4/CXCL12 hyperexpression plays a pivotal role in the pathogenesis of lupus. J Immunol 182(7):4448-58. Assay: Urea in mouse blood.

Zafar, I., et al. (2009). Long-term rapamycin therapy in the Han:SPRD rat model of polycystic kidney disease (PKD). Nephrol Dial Transplant 24(8):2349-53. Assay: Urea in rat blood.

Fairhurst, A.M., et al. (2008). Yaa autoimmune phenotypes are conferred by overexpression of TLR7. Eur J Immunol 38(7):1971-8. Assay: Urea in mouse blood.

He, Z., et al. (2008). Interleukin-18 binding protein transgenic mice are protected against ischemic acute kidney injury. Am J Physiol Renal Physiol 295(5):F1414-21. Assay: Urea in mouse blood.

Meng, Q., et al. (2008). Regulating the age-related oxidative damage, mitochondrial integrity, and antioxidative enzyme activity in Fischer 344 rats by supplementation of the antioxidant epigallocatechin-3-gallate. Rejuvenation Res 11(3):649-60. Assay: Urea in rat plasma, urine.

Moertel, L., et al. (2008). Comparative real-time PCR and enzyme analysis of selected gender-associated molecules in Schistosoma japonicum. Parasitology 135(5):575-83. Assay: Urea in Schistosoma japonicum protein extract; arginase activity.

Pauwels, F.E., et al. (2008). Evaluation of the diffusion of corticosteroids between the distal interphalangeal joint and navicular bursa in horses. Am J Vet Res 69(5):611-6. Assay: Urea in horse tissue.

Ramalingam, T.R., et al. (2008). Unique functions of the type II interleukin 4 receptor identified in mice lacking the interleukin 13 receptor alpha1 chain. Nat Immunol 9(1):25-33. Assay: Urea in mouse macrophage.

Yang, B., et al. (2008). Small-molecule CFTR inhibitors slow cyst growth in polycystic kidney disease. J Am Soc Nephrol 19(7):1300-10. Assay: Urea in mouse serum.

Botha, P., et al. (2007). Inhaled nitric oxide for modulation of ischemia-reperfusion injury in lung transplantation. J Heart Lung Transplant 26(11):1199-205. Assay: Urea in animal bronchoalveolar lavage.

Horowitz, S., et al. (2007). Increased arginase activity and endothelial dysfunction in human inflammatory bowel disease. Am J Physiol Gastrointest Liver Physiol 292(5):G1323-36. Assay: Urea in human intestine tissue.

Rodriguez-Iturbe, B., et al. (2007). Association of mitochondrial SOD deficiency with salt-sensitive hypertension and accelerated renal senescence. J Appl Physiol 102(1):255-60. Assay: Urea in mouse plasma.

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