Uric Acid (on ice-Elitek)
Label Mnemonic: URICICE
Epic Lab Code: LAB870
Downtime Form: A-1a General Laboratory Requisition
Chemistry
6240 RCP
356-3527
Specimen(s):
Plasma
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
Minimum:
3 mL whole blood in PRECHILLED light green top tube or one PRECHILLED Microtainer® for pediatric patients.
Delivery Instructions:
Keep on ice and deliver to laboratory immediately.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
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
Comments:
This test is specifically for patients who are taking the drug rasburicase (Elitek). Collection in pre-chilled tubes and rapid transport limits breakdown of uric acid by the uricase enzyme in the blood tube.
Test Limitations:
If directions for specimen collection (pre-chilled tube and deliver on ice) are not followed, a false low uric acid will result. 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 1500. There is poor correlation between turbidity and triglycerides concentration. Ascorbic acid less than 3 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.
Methodology:
Enzymatic Colorimetric
CPT Code:
84550
 
See also:
Uric Acid, Plasma