Test Overview
Test Methodology

Colorimetric (Xylidyl Blue)

Test Usage

Evaluation of metabolic disorders, monitoring level in patients on long term intravenous therapy.

Reference Range *

1.5 - 2.4 mg/dL

Test Details
Days Set Up
Daily, 24 hours
Analytic Time

2 hours

Soft Order Code
MAG
MiChart Code
Magnesium
Synonyms
  • OBMAG
  • Mg
  • MAG
  • MAGNESIUM LEVEL
  • MAGNESIUM LEVEL, OBSTETRICS
Laboratory
Chemical Pathology
Section
Automation
STAT Availability

STAT requests for this test will be performed on a STAT basis (supervisory staff approval is not required).

Specimen Requirements
Collection Instructions

Collect specimen in an SST tube. Centrifuge, aliquot serum into a plastic vial and refrigerate. Grossly hemolyzed, icteric or lipemic samples may cause a significant interference with this assay.

Alternate Specimen
Red top, Green top (sodiuim or lithium heparin) tube. [rev 11/09]
Yellow Top Tube
Normal Volume
0.5 mL serum
Minimum Volume
0.25 mL serum
Additional Information

Magnesium Level, Obstetrics (OBMAG) is available for Obstetrics use only for patients receiving MgSO4. The magnesium reference range for these orders is 1.5 - 8.0 mg/dL with a critical callback value of greater than 8.0 mg/dL. These results are also accompanied by the following interpretation: "Therapeutic range for OB patients on MgSO4 for seizure prophylaxis is 4.0 - 8.0 mg/dL."

Billing
CPT Code
83735
Fee Code
20704
LOINC
19123-9
NY State Approved
No