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HelpTest Code LAB748 Urea Nitrogen, Urine, Random
Performing Laboratory
St. Louis Children's Hospital Laboratory - Chemistry
Specimen Requirements
Patient Preparation: None
Collection Container/Tube:
Preferred: Clean, plastic screw-cap urine collection container with no preservatives
Acceptable: Any clean, plastic collection container, no preservatives
Specimen Collection Volume: 5.0 (minimum 0.5 mL) urine
Submission Container/Tube: If specimen is coming from outside facility aliquot a minimum of 0.5 mL of urine into a plastic, leak-proof, screw-capped tube for transport.
Special Instructions: None
Sample Rejection
Mislabled or unlabeled specimens
Logistics
Test Availability: Monday-Sunday
Cut-off time: None, performed as received
Turnaround Time: Same Day; 2 hours from receipt in performing lab
Reference Values
Reference Interval: No reference intervals established
Critical Value: None established
Methodology
Kinetic test (Urease with Glutamate Dehydrogenase) measured photometrically
Limitations
- NA
Additional Information
FOR SLCH CORE LABORATORY USE ONLY
Lab Processing Instructions: Mix well and aliqout minimum of 0.5 urine into a Roche-false bottom tube. If specimen is turbid or precipitates are present, mix well and aliquot into plastic container to centrifuge to clear then aliquot cleared urine into the Roche-false bottom tube for testing.
Processed Volume: minimum 0.3 mL urine
Analyte Stability:
| Specimen Type | Temperature | Time |
|---|---|---|
| urine (no preservative) | Ambient | 2 days |
| Refrigerated | 3 days | |
| Frozen | 1 month |
Test Classification and CPT Code
84540
LOINC
3095-7
Last Reviewed
07/2025