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Test Code Mg RBC Magnesium, Red Blood Cell

Profile Information

Test ID Reporting Name Available Separately Always Performed
Z4363 Magnesium, RBC No Yes
Z4364 Magnesium, Plasma No No

Reporting Name

Magnesium, RBC

Specimen Type

Metal Free EDTA Plasma

Specimen Required

Collect whole blood from a metal-free EDTA (royal blue top) tube. Spin down and separate plasma and red blood cells immediately. Ship 2 mL plasma and 2 mL RBC in metal-free tubes, refrigerate.


NOTE: Both plasma and RBCs are required for testing.

Seattle Children's Hospital Note:

Do not send remaining RBC's in it's original glass tube. Transfer RBC's into another plastic metal-free aliquot tube.

Specimen Minimum Volume

0.3 mL

Specimen Stability Information

Specimen Type Temperature Time
Metal Free EDTA Plasma Refrigerated (preferred) 5 days
  Ambient  72 hours
RBCS Refrigerated (preferred) 5 days
  Ambient  72 hours

Reject Due To


Mild reject; Gross reject








All other collection tubes except Royal blue-top metal free EDTA

Reference Values

3.5 - 7.1 mg/dL

Day(s) and Time(s) Performed

Monday through Sunday

Performing Laboratory

Medtox Laboratories, Inc.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
FMAGR Magnesium, RBC In Process


Result ID Test Result Name Result LOINC Value
Z4363 Magnesium, RBC 26746-8
Z4364 Magnesium, Plasma 19123-9

Method Name

Inductively Coupled Plasma/Mass Spectrometry (ICP-MS)