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Test Code MAGRBC Magnesium, RBC  

Important Note

Centrifuge tube within 45 minutes of collection and separate as much  plasma from cells as possible. Send the plasma and the original collection tube with  RBCs to the laboratory.


Collection Container

Green-top (heparin) tube, lavender-top (EDTA) tube, royal blue-top (EDTA) tube, or tan-top lead-free tube (SEE ORDERING NOTE)

Specimen Required

Submit plasma and RBC's in original tube to chemistry laboratory.

Specimen Volume

1 mL Red blood cells, RBC'S (From proper tube type)

Minimum Specimen Volume

0.2 mL Red blood cells, RBC's (From proper tube type)

Transport Temperature

Room temperature

Specimen Stability

Room temperature

14 days


14 days,


14 days

Freeze/thaw cycles

Stable x3


Atomic absorption spectrometry (AAS); inductively-coupled plasma/mass spectrometry (ICP/MS)

Reference Ranges

4.2−6.8 mg/dL

CPT Code


Cause for rejection

Serum or plasma specimen