Lt green plasma separator (PST)

The following special sample handling procedure must be followed to avoid ex vivo uric acid degradation:

• Uric acid must be collected in heparinized plasma tubes
• Immediatley following collection, mix sample thoroughly by gentle inverting 8 - 10 times, to prevent clotting
• Samples must be immediately immersed in an ice water bath

Centrifuge at 3,000 - 3,200 RPM for 5 minutes.

Samples are to be run immediately after centrifugation or the tube must be placed in an ice water bath and analyzed for uric acid within four (4) hours of collection.

Lt green plasma separator (PST)

Refrigerated/on ice - 4 hours

Enzymatic Colorimetric assay

Roche:

Rasburicase is a recombinant urate-oxidase enzyme approved for use by the FDA in patients who are at risk of developing tumor lysis syndrome or for the management of elevated uric acid levels. Rasburicase catalyzes enzymatic oxidation of uric acid into an inactive and soluble metabolite allantoin. At room temperature, ELITEK causes enzymatic degradation of the uric acid in blood, plasma, and serum samples potentially resulting in spuriously low plasma uric acid assay readings.