The competitive Normetanephrine and Metanephrine (Urine) ELISA kit uses the microtiter plate format. Metanephrine and normetanephrine, respectively, are bound to the solid phase of the microtiter plate. Acylated nor-/metanephrines from the sample and solid phase bound nor-/metanephrines compete for a fixed number of antiserum binding sites. When the system is in equilibrium, free Antigens and free Antigens-antiserum complexes are removed by washing. The antibody bound to the solid phase nor-/metanephrine is detected by anti-rabbit IgG / peroxidase. The substrate TMB / peroxidase reaction is monitored at 450 nm. The amount of antibody bound to the solid phase nor-/metanephrines is inversely proportional to the nor-/metanephrines concentration of the sample. Sample Types: urine. Range: Metanephrine: 20-2400 ng/ml, Normetanephrine: 30 - 4000 ng/ml. Sensitivity: Metanephrine: 4 ng/ml, Normetanephrine: 10 ng/ml. Time: 3 hours ? Normetanephrine and metanephrine are physiologically formed from the catecholamines noradrenaline and adrenaline by the enzyme catechol-O-methyltransferase (COMT). Increased levels of normetanephrine and metanephrine can be found in pheochromocytoma, ganglioneuroma and other neurogenic tumors. The Normetanephrine and Metanephrine (Urine) ELISA assay kit provides materials for the quantitative measurement of normetanephrine and metanephrine in urine. Normetanephrine and metanephrine are quantitatively acylated to their N-acyl-derivates.