Skip to Content
UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: BUN

Test Code(s): BUN

CPT Code(s): 84520

Test Description: Included In: Basic Metabolic Panel, Comprehensive Metabolic Panel

Methodology: Urease

Days Performed: Daily, 24 hours.

Turnaround Time: Stat: 1 hour.
Routine: 4 hours.

Specimen Requirements

Specimen: Blood

Collection Container: Preferred: Green cap with yellow ring (PST)
Also Acceptable: Green top, Red cap with yellow ring (SST), Red top

Collection Volume: Preferred: 1 mL
Pediatrics: 0.4 mL

Sample Analyzed: Plasma or serum

Volume Required: Preferred: 0.5 mL
Pediatrics: 0.2 mL

Specimen Processing: Centrifuge.  If a complete barrier has not formed, transfer cell-free plasma/serum to plastic vial.  Refrigerate.

Specimen Transport: Transport specimen to the laboratory. Transport with coolant pack if coming from outreach location.

Stability: Ambient: 3 days
Refrigerated: 7 days
Frozen: Indefinitely


Reference Interval:
Age mg/dL  
1-5 years 5-18
6 years and up   7-20 


Critical Calls: View

Blood Urea Nitrogen

Back to Lab Test Directory Index