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Bilirubin, Direct

Conjugated Bilirubin

Testing Information

Sample Type
Test Codes
CPT Code
Testing Area
Core Lab - Chemistry
Test Methodology
Abbott Alinity - Spectrophotometry
Reference Range
0-4 weeks: ≤1.0 mg/dL>4 weeks: 0.0-0.4 mg/dLCritical Value: 0-4 weeks only: ≥2.0 mg/dL
Expected Turnaround Time
Results Available 24 hours from Receipt at the laboratory.
Specimen Collection Criteria
Collect one gold top SST tube (minimum whole blood: 4 mL). Let specimen clot for 30-60 minutes and then centrifuge to separate serum from cells. Refrigerate after centrifugation. Protect from light.
Rejection Criteria
Grossly hemolyzed specimens, quantity not sufficient, improperly labeled
Specimen Validity and Retention
Centrifuged SST Tubes:Room Temperature (20-25°C): 2 daysRefrigerated (2-8°C): 7 daysFrozen (-20°C or greater): UnacceptableSerum AliquotsRoom Temperature (20-25°C): 2 daysRefrigerated (2-8°C): 7 daysFrozen (-20°C or greater): 7 daysSpecimens retained for 7 days after testing
Courier Transportation
Transport centrifuged tube refrigerated (2-8°C). Protect from light.
Clinical Utility
Direct bilirubin is useful in the evaluation of liver and biliary disease.