Urea Nitrogen, Random Urine

Additional Information:

UFHPL Epic order code: LAB748

CPT Code(s):


Specimen Requirements:

Type: Urine, random

Container/Tube: Plastic urine container with no preservative

Sample Volume: 1 mL

Storage: Refrigerate specimens.

Specimen Retention Time: 5 days


Urea is hydrolyzed enzymatically by urease to yield ammonia and carbon dioxide. The ammonia and a-oxoglutarate are converted to glutamate in a reaction catalyzed by L-glutamate dehydrogenase (GLDH). Simultaneously, a molar equivalent of reduced NADH is oxidized. Two molecules of NADH are oxidized for each molecule of urea hydrolyzed. The rate of change in absorbance at 340 nm, due to the disappearance of NADH, is directly proportional to the BUN concentration in the sample. (Package Insert, OSR General Chemistry, BAOSR6x34.03 OSR; 2014-04)


Within 24 hours

Reference Values:

No reference range established