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HelpTest Code MG Magnesium, LAB103
Performing Laboratory
St. Luke's Hospital Cedar Rapids
Specimen Requirements
Container/Tube:
Preferred: Green-top (heparin) tube-Hemolyzed specimen is not acceptable.
Acceptable: Gold-top serum gel tube or plain red-top tube
Specimen Volume: A minimum sample volume of 2.4 µL plus a dead volume
Stability: Serum or plasma should be separated from the cells within 2 hours of collection.
Specimens may be stored at 2 – 25°C for 7 days and up to 12 months at -20°C or colder.
Urine samples should be acidified to pH 1 with concentrated HCL to prevent the precipitation of magnesium ammonium phosphate. Collect urine samples in a metal-free container. Urine samples are automatically prediluted with 0.9 % NaCl by the instrument. If stabilizers are added to the sample, the sample index feature must not be used. Urine specimens are stable for 3 days at 2-25 ⁰C or 1 year at -15 to -25 ⁰C
Reference Values
|
Serum/Plasma Age |
Normal Range (mg/dL) |
Critical Low (mg/dL) |
Critical High (mg/dL) |
|
0-31 Days |
1.5-2.2 |
1.0 |
4.7 |
|
5 Months - 6 Years |
1.7-2.3 |
1.0 |
4.7 |
|
6 Years - 12 Years |
1.7-2.1 |
1.0 |
4.7 |
|
12 Years - 20 Years |
1.7-2.2 |
1.0 |
4.7 |
|
20 Years – 60 Years |
1.6-2.6 |
1.0 |
4.7 |
|
60 Years – 91 Years |
1.6-2.4 |
1.0 |
4.7 |
|
≥91 Years |
1.6-2.4 |
1.0 |
4.7 |
Urine: 72.9-121.5 mg/24hr
Day(s) Test Set Up
Monday through Sunday
Useful For
Magnesium measurements are used in the diagnosis and treatment of hypomagnesemia (magnesium deficiency) and hypermagnesemia (magnesium excess).
Methodology
Colorimetric endpoint method
Test Classification and CPT Coding
83735
Report Available
STAT within 1 hour of receipt.
Routine within 2 hours of receipt.