PRINCIPLE AND REFERENCE VALUES: The Renal Function Test Strip use a timed-endpoint method to measure the Uric Acid (UA),Creatinine (CR) and Urea (UR) concentrations in whole blood, serum or plasma. The system monitors the change in absorbance at 620 nm at a fixed-time interval. The change in absorbance is directly proportional to the concentration of metabolite in the specimen. UA: In the reaction, the uric acid is oxidized to allantoin and hydrogen peroxide by uricase. Peroxidase catalyzes the reaction of hydrogen peroxide with 4-aminoantipyrine and phenol to produce a colored quinoneimine product. The change in absorbance is directly proportional to the concentration of uric acid in the specimen. CR: Creatinine in the specimen are hydrolyzed to creatine by the action of creatininase. A sequence of three coupled enzymatic steps using creatinase, sarcosine oxidase, and peroxidase causes the oxidative coupling of 4-aminoantipyrine to form a blue dye. UR: Urea in the specimen are hydrolyzed to NH3 and CO2 by the action of ureaseand an indicator layer containing an indicator which produces a detectable change by gaseous ammonia.