Sign in →

Test Code MG Magnesium, Plasma or Serum

Additional Codes

Compendium Code (Iatric): L300.1650

Performing Laboratory

St. Lukes Hospital Laboratory

Methodology

Colorimetric with Xylidyl Blue

Specimen Requirements

Separated specimens may be stored for up to 7 days at 2 - 8°C.

Submit only 1 of the following specimens:
 
Plasma
Draw blood in a green-top (lithium heparin) plasma gel tube(s). Spin down and send 1 mL of lithium heparin plasma refrigerated.
Note:  1. Indicate plasma on request form.
2. Label specimen appropriately (plasma).
 
Serum
Draw blood in a serum gel tube(s). Spin down and send 1 mL of serum refrigerated.
Note:  1. Indicate serum on request form.
2. Label specimen appropriately (serum).

 

 

Unspun specimens must be transported at ambient temperature and arrive to the laboratory within one hour of draw.

Reference Values

1.5-2.4 mg/dL

Critical values (automatic call-back):  <0.5 mg/dL or >5 mg/dL

Interfering Substances:

Hemolysis will cause an increase in magnesium. Lipemia can cause falsely-decreased magnesium.

Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding

CPT: 83735

LOINC: 19123-9