Magnesium, Urine
Also known as: UMG
Use
Magnesium is an essential mineral involved in numerous physiological processes, including bone formation, energy production, and regulation of muscle and nerve function. Measuring magnesium levels in urine can help evaluate magnesium metabolism and is particularly useful for diagnosing and monitoring conditions associated with magnesium imbalance, such as nephrolithiasis (kidney stones). The 24-hour urine collection allows for the assessment of magnesium excretion over a full day, providing insight into kidney function and potential disorders related to magnesium homeostasis.
Special Instructions
Collect a 24-hour urine sample, refrigerating during collection. Adjust the specimen pH to 1 with 6M HCl, using approximately 10 mL per 24-hour specimen. Ensure to record total volume and the collection interval on both the transport tube and test request form. Transfer a 4 mL aliquot to an ARUP Standard Transport Tube. When performing pediatric collections, less than 10 mL of HCl is necessary to achieve the proper pH.
Limitations
The test results may be compromised if the urine specimen has a pH greater than 2.0 or if it contains preservatives other than HCl. Urine specimens collected in metal containers are unacceptable. Calculation ratios with urine creatinine concentrations may assist in interpretation for specimens with deviations from 24-hour collection or average volume. Ambient stability is 3 days if acidified, refrigerated stability is 2 weeks, and the sample can be frozen for up to a year.
FDA ApprovedNew York Approved
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 19153-6
- 2162-6
- 24447-5
- 30211-7
- 30922-9
- 35674-1
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
4 mL
Minimum Volume
0.5 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Adjust pH to 1 by adding 6M HCl, record volume and collection time on the transport tube and test request form.
Patient Preparation
Collect 24-hour urine. Refrigerate during collection.
Storage Instructions
Refrigerate the specimen during transport. Ambient: 3 days if acidified; Refrigerated: 2 weeks; Frozen: 1 year
Causes for Rejection
Specimens containing preservatives other than HCl. Specimen submitted in metal containers.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 3 days (if acidified) |
| Refrigerated | 2 weeks |
| Frozen | 1 year |