Specimen:

Plasma

Collection Medium:

Alternate
Collection Media:

Call laboratory for additional acceptable specimen collection 
containers.

Minimum:

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

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)

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

Test
Limitations:

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

Sample
Processing:

Centrifuge at 3000 RPM for 10 minutes.
Aliquot plasma into labeled container and cap.

Sample
Storage:

Room temperature or refrigerate if stored overnight.

Transport
Instructions:

Place specimen into zip-lock type bag, seal bag.
Place requisition into outside pocket of bag.
Ship ambient or refrigerate.

CPT Code:

84550