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HelpTest Code MAGNR Magnesium, Random, Urine
Useful For
Assessing the cause of abnormal serum magnesium concentrations
Determining whether nutritional magnesium loads are adequate
Calculating urinary calcium oxalate and calcium phosphate supersaturation and assessing kidney stone risk.
Method Name
Colorimetric Endpoint Assay
Reporting Name
Magnesium, Random, USpecimen Type
UrineSpecimen Required
Collection Container/Tube: Plastic urine container
Submission Container/Tube: Plastic, 5-mL tube (T465) or a clean, plastic aliquot container with no metal cap or glued insert
Specimen Volume: 4 mL
Collection Instructions:
1. Collect a random urine specimen.
2. No preservative.
Specimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 14 days | |
| Frozen | 14 days | ||
| Ambient | 72 hours |
Reject Due To
| All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. |
Reference Values
Random Magnesium/Creatinine Ratio: ≥0.035 mg/mg
Reference values have not been established for patients <18 years and >83 years of age.
Day(s) and Time(s) Performed
Monday through Sunday; Continuously.
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test has been modified from the manufacturer’s instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
83735
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| MAGNR | Magnesium, Random, U | 19124-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| MGCO | Magnesium, Random, U | 19124-7 |
| CREA7 | Creatinine Concentration | 2161-8 |
| MCTR | Magnesium/Creatinine Ratio | 13474-2 |
Forms
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.