Laboratory test

Clinical Chemistry

Uric Acid

Uric Acid is a Clinical Chemistry laboratory test reference in the LabPedia Medical Laboratory Library. Serum/plasma urate measurement used in gout evaluation, tumor lysis monitoring, and selected metabolic assessments.

Also known asUrate; Serum uric acid

Overview

Uric acid is the end-product of purine metabolism measured as circulating urate.

Clinical Importance

Support gout/hyperuricemia evaluation

Monitor tumor lysis and selected therapies

Specimen Requirements

  • Specimen: serum or lithium heparin plasma (method- and analyzer-dependent; follow the performing laboratory)
  • Tube: gold/SST (serum separator) or green-top lithium heparin as validated locally
  • Handling: invert gently; allow SST to clot fully before centrifugation; separate promptly
  • Storage: refrigerate serum/plasma if testing is delayed per analyte stability limits
  • Stability: analyte-specific; do not exceed institutional or manufacturer time/temperature limits
  • Fasting: follow institutional/protocol fasting requirements when the ordered pathway requires fasting

Analytical Method

Uricase enzymatic methods with photometric detection on chemistry analyzers.

Instruments Used

Automated analyzers

  • Roche Cobas chemistry and immunoassay systems
  • Abbott Alinity / Architect chemistry and immunoassay systems
  • Siemens Healthineers Atellica / ADVIA chemistry and immunoassay systems
  • Beckman Coulter AU / DxC chemistry systems
  • Beckman Coulter Access / DxI immunoassay systems
  • Mindray BS-series chemistry analyzers
  • Ortho Clinical Diagnostics Vitros systems
  • Thermo Fisher / Indiko and related chemistry platforms
  • Randox clinical chemistry systems

Manual methods

  • Manual spectrophotometric/immunoassay methods in selected reference or backup settings

Reference Values

Typical adult SI examples below follow widely published international clinical chemistry practice (e.g., Tietz; Henry's). Always interpret against the method- and demographics-specific interval printed on the patient report (CLSI EP28-A3c). Neonatal, pediatric, pregnancy, and assay-generation intervals differ.

Typical published adult intervals often approximate 210–420 µmol/L (3.5–7.0 mg/dL) in men and slightly lower in premenopausal women; method and lab specific.

Interpretation

Common Causes of Increased Results

  • Hyperuricemia; overproduction or underexcretion patterns

Common Causes of Decreased Results

  • Hypouricemia; renal wasting, SIADH context, or rare enzymatic defects

Clinical Significance

  • Gout laboratory support (not a stand-alone diagnosis)
  • Tumor lysis laboratory monitoring

Factors Affecting Results

Pre-analytical

  • Hemolysis, lipemia, or icterus (analyte- and method-dependent interference)
  • IV fluid contamination or draw above an infusion
  • Prolonged tourniquet time; delayed separation of cells
  • Wrong tube additive or incomplete clotting of SST

Analytical

  • Calibration/QC failure; reagent lot shifts
  • Carryover or substrate depletion on high-throughput analyzers
  • Assay-specific interference (heterophile antibodies for immunoassays)

Post-analytical

  • Wrong reference interval or unit applied
  • Failure to review delta checks / critical values before release

Advantages and Limitations

Advantages

  • Automated, widely available

Limitations

  • Serum urate may be normal during acute gout flares
  • Does not replace synovial fluid crystal analysis for gout diagnosis

Clinical Pearls

A normal uric acid during an acute hot joint does not exclude gout; crystals still rule.

References

Authoritative textbooks, guidelines, and reviews supporting this laboratory test reference. Verify reference intervals, critical limits, and method details against institutional protocols and current guideline editions.

Textbooks

  • Rifai N, Horvath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 8th ed. Elsevier; 2022.
  • McPherson RA, Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Elsevier; 2021.
  • Bishop ML, Fody EP, Schoeff LE. Clinical Chemistry: Principles, Techniques, and Correlations. 9th ed. Jones & Bartlett; 2022.

CLSI and Professional Guidelines

  • International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). Recommendations and reference measurement systems for clinical chemistry measurands (verify current IFCC documents for the analyte).
  • Clinical and Laboratory Standards Institute. Defining, Establishing, and Verifying Reference Intervals in the Clinical Laboratory; Approved Standard. CLSI document EP28-A3c. CLSI; 2010.
  • Clinical and Laboratory Standards Institute. Collection of Diagnostic Venous Blood Specimens. CLSI standard GP41. CLSI.
  • American Diabetes Association. Standards of Care in Diabetes. Diabetes Care (annual update).
  • Kidney Disease: Improving Global Outcomes (KDIGO). Clinical Practice Guideline for Evaluation and Management of Chronic Kidney Disease.
  • American Association for the Study of Liver Diseases (AASLD). Practice guidance related to evaluation of abnormal liver chemistries / liver disease laboratory evaluation (verify current AASLD publication and institutional adoption).

Frequently Asked Questions

Common questions about using this Uric Acid laboratory test Medical Laboratory Library reference in Medical Laboratory Science education.

What is the Uric Acid laboratory test reference used for?

This Medical Laboratory Library page summarizes the clinical importance of Uric Acid. Review the Clinical Importance section for why the test is ordered in laboratory medicine practice.

Where can I find Uric Acid specimen requirements?

See the Specimen Requirements section on this page for specimen information related to Uric Acid. Confirm collection details against your laboratory protocol.

Where are Uric Acid reference values listed?

See the Reference Values section on this Laboratory Library page. Reference ranges can vary by method and population, so verify intervals with your laboratory.

How do I interpret Uric Acid results?

Use the Interpretation section for laboratory interpretation framing, including increased and decreased result patterns when provided. Do not treat educational text as a patient-specific diagnosis.

What analytical method is used for Uric Acid?

See the Analytical Method section for principle and method notes. Method details may differ by instrument and institutional SOP.

Are related laboratory tests linked from Uric Acid?

Yes. The Related Laboratory Tests section lists connected references for continued lookup in the Medical Laboratory Library.

How can I continue learning after reading Uric Acid?

Use Continue learning links on this page for related Academy lessons, medical laboratory quizzes, or laboratory case studies when available for this Clinical Chemistry topic.

What are the clinical pearls for Uric Acid?

See the Clinical Pearls section for concise laboratory practice notes associated with Uric Acid. Apply pearls alongside institutional protocols.

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