Lead/Creatinine Ratio, U
Use
Detecting clinically significant lead exposure using random urine specimens. This test is not a substitute for blood lead screening. Increased urine lead concentration per gram of creatinine indicates significant lead exposure and may be used to monitor response to chelation, though post‑chelator challenge urinary metal testing is not scientifically validated and may be harmful. Blood lead measurement remains the best clinical correlate. ([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/Overview/608908?utm_source=openai))
Special Instructions
Only orderable as part of profile PBUCR or HMUCR. Not available separately. ([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/Overview/608908?utm_source=openai))
Limitations
Not a substitute for blood lead screening. Post‑chelation urinary testing has not been validated and may be harmful (per ACMT 2010 position statement). Blood lead measurement remains the most appropriate test for clinical toxicity correlation. ([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/Overview/608908?utm_source=openai))
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 13466-8
- 13466-8
- 2161-8
Result Turnaround Time
2-4 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
Not provided
Minimum Volume
1.5 mL
Container
Clean, plastic urine container with no metal cap or glued insert; plastic 10‑mL urine tube or clean plastic aliquot container with no metal cap or glued insert
Collection Instructions
Random urine; high concentrations of gadolinium or iodine contrast agents interfere; delay collection 96 hours post‑contrast.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 28 days |
| Frozen | 28 days |