For quantitative determination of urea and evaluation of drug effects on urea metabolism. Key Features: Sensitive and accurate. Use 5 µ L samples. Linear detection range 0.08 mg/dL (13 µ M) 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.