Confirm 3.4-7.0 mg/dL (males) and 2.4-5.7 mg/dL (females) Pediatric Reference Ranges: Age Range Units 0-2 years 2.0-7.0 mg/dL 2-12 years 2.0-6.5 mg/dL 12-14 years 2.0-7.0 mg/dL

Criterion: Recovery within plus or minus 10% of initial values Plasma Icterus: No significant interference up to an I index of 40 (approximate conjugated and unconjugated bilirubin concentration 40 mg/dL or 684 umol/l). Hemolysis: No significant interference up to an H index of 1000 (approximate hemoglobin concentration: 1000 mg/dL or 621 umol/l). Lipemia (Intralipid): No significant interference up to an L index of 1000 (approximate triglycerides concentration: 2000 mg/dL or 22.8 mmol/l). There is poor correlation between turbidity and triglycerides concentration. Ascorbic acid less than 30 mg/dL does not interfere. Of the drugs tested in vitro, o-methyldopa, desferoxamine and calcium dobesilate (e.g. Dexium) cause interference at therapeutic concentrations (uric acid level artificially low). Uricase reacts specifically with uric acid. Other purine derivatives can inhibit the uric acid reaction. Reference: Glick MR, Ryder KW, Jackson SA. Graphical Comparisons of Interferences in Clinical Chemistry Instrumentation. Clin Chem 1986;32:470-474.