Home
HelpTest Code LAB748 Urea Nitrogen, Urine, Random
Performing Laboratory
Barnes-Jewish Hospital Laboratory
Methodology
Enzymatic (Urease)
Literature Reference:
Package insert: Urea/BUN UREAL reagent. Roche Corporation, 01/2016.
Specimen Requirements
Specimen Type: Urine, random
Container/Tube: Urine Complete Cup Kit
Specimen Volume: 10 mL
Collection Instructions: No additive.
Additional Information: See Urine Collection information under General Information.
Day(s) Test Set Up
Monday through Sunday
Turnaround Time:
STAT: 1 hour after receipt in laboratory
Routine: 2 to 4 hours after receipt in laboratory
Test Classification and CPT Coding
84540
Reference Values
No established reference intervals
Note: Calculation of nitrogen balance requires knowledge of 24-hour urea nitrogen and daily protein intake. Use the following formula: nitrogen balance=daily protein intake (g)/6.25-(24 hour urine urea nitrogen+3 or 4*).
*Use 4 if diarrhea is present.
Literature Reference:
Rifai N, Horvath AR, Wittwer AT eds: Textbook of Clinical Chemistry and Molecular Diagnostics 6 th ed: Chapter 32, p. 479, Elsevier, St. Louis, MO 2018.
Specimen Transport Temperature
Ambient
Additional Information
For BJH Laboratory Use Only
Analyte Stability:
Specimen must be kept refrigerated during collection and before delivery to limit bacterial growth.
Laboratory Processing Instructions:
Test performed in BJH Core Lab. Mix urine well. Using 13x100 test tubes, prepare a 7-mL aliquot and deliver to the automated line for centrifugation and delivery to Cobas 8000 for analysis. Completed specimen is stored refrigerated for 5 days.
Special Instructions
See Urine Collection information under General Information.
See Analyte Stability Chart under General Information for a complete list
LOINC Code Information
| Name | LOINC Code |
| Urea Nitrogen in urine | 3095-7 |