title: Direct enzymatic determination of urea in plasma and urine with a centrifugal analyzer.
abstract: A direct enzymatic micromethod (sample volume, 3mul) has been adapted to the centrifugal analyzer (ENI-GEMSAEC) for measurement of urea in plasma and urine. The method is based on urease (urea amidohydrolase, EC3.5.1.5)/glutamate dehydrogenase [l-glutamate:NAD(P)+oxidoreductase (deaminating), EC1.41.3] coupled reactions, and uses a two-point fixed-time (t(1)=20s,t(2)=50s)kinetic scheme for monitoring the rate of comsumption of NADH at 340 nm. Sensitivity and precision of the method are excellent,and results compare well with those from a commonly used continuous-flow method.
mesh_terms: D001322:Autoanalysis; D002498:Centrifugation; D005969:Glutamate Dehydrogenase; D006801:Humans; D008722:Methods; D008832:Microchemistry; D014508:Urea / Q000032:analysis* / Q000097:blood / Q000652:urine; D014510:Urease
chemical_list: D014508:Urea; D005969:Glutamate Dehydrogenase; D014510:Urease