Ordering Recommendation

May be useful in the assessment of tissue stores. For routine assessment of magnesium deficiency, Magnesium, Plasma or Serum (0020039) is preferred.


Quantitative Inductively Coupled Plasma-Mass Spectrometry




1-4 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation

Royal Blue (EDTA).

Specimen Preparation

Centrifuge whole blood and separate RBCs from plasma within 2 hours of collection. Transfer 2 mL RBCs to an ARUP Trace Element-Free Transport Tube (ARUP supply #43116) available online through eSupply using ARUP Connect™ or contact ARUP Client Services at (800) 522-2787. (Min: 0.6 mL)

Storage/Transport Temperature

Room temperature. Also acceptable: Refrigerated.

Unacceptable Conditions

Specimens collected in tubes other than royal blue (EDTA). Specimens transported in containers other than Royal Blue (EDTA) tube or Trace Element-Free Transport Tube. Clotted or grossly hemolyzed specimens.


After separation from plasma: Ambient: 1 week; Refrigerated: 1 week; Frozen: Unacceptable

Reference Interval

1.5-3.1 mmol/L

Interpretive Data

RBC magnesium results reflect the intracellular stores and general homeostasis of magnesium. Results may be falsely low if RBCs in the submitted specimen are lysed or not promptly separated from plasma. To convert to mg/dL, multiply mmol/L by 2.43.

Compliance Statement B: For laboratory developed tests not using a RUO kit, and for FDA approved, cleared or 510(k) exempt assays with alterations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Hotline History
CPT Codes


Component Test Code* Component Chart Name LOINC
0092080 Magnesium, RBCs 2597-3
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
  • Intracellular Magnesium
  • MgRBCs
Magnesium, RBC