Blood Urea Nitrogen (BUN) (1006)

Create a Free Account to View Prices

CPT Code:


Test Type: Serum Kit Based
Stability Time:


Refrigerated: 7 days

Reference Range:
  • Low: <3.0 mg/dL
  • Normal: 3.0-25.0 mg/dL
  • High: >25.0 mg/dL
  • Alert: >50.0 mg/dL


Urea is the major end product of protein nitrogen metabolism. Urea is synthesized in the liver and excreted mostly by the kidneys.

Elevated levels of BUN usually indicate renal damage or mechanical obstruction of urine excretion.

Methodology - Enzymatic

Collection Details:

Collection Instructions:

Preferred Specimen

1.0 mL serum (0.5 mL minimum) collected in serum separator tube (SST/Tiger Top)

Alternate Specimen

1.0 mL EDTA plasma (0.5 mL minimum) collected in plasma separator tube (Pearl Top)

Transport Temperature

Refrigerated (ship on frozen cold packs)