Specimen

Plasma

Collection Medium:

Alternate
Collection Media:

Call laboratory for additional acceptable specimen collection 
containers.

Minimum:

2 mls whole blood in PRECHILLED light green top tube or one PRECHILLED 
microtube for pediatric patients

Delivery Instructions:

Keep on ice and deliver to laboratory immediately.

Testing Schedule:

24 hrs/day, 7 days a week, including holidays.

Analytic Time:

2 hours (upon receipt in laboratory)

Reference Range:

Confirm 3.4-7.0 mg/dl (males) and 2.4-5.7 mg/dl (females)

Comments:

This test is specifically for patient who are taking the drug 
rusburicase (Elitek).

Test
Limitations:

If directions for specimen collection (prechilled 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 
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 
calciumdobesilate (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

CPT Code:

84550

See also:
Uric Acid, Plasma

See Additional Information:
Chemistry Pediatric Reference Ranges
Specimens Requiring Immediate Delivery