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Test Code MG Magnesium

Additional Codes

Epic: LAB103

Specimen Required

Specimen Type: Serum

Collection Container/Type

Preferred: Serum gold

Acceptable: Green top (Lithium heparin)

Submission Container/Tube: Plastic vial

Specimen Volume: 3.5 mL

Collection Instructions: Centrifuge and separate cells after clot formation and within 4 hours of collection.  

Additional Information:

Specimen Minimum Volume

0.5 mL

Specimen Stability

Room temperature: 7 days

Refrigerated: 7 days

Frozen: 1 year

Reference Range

0 - 18 years: 1.3 - 2.2 mg/dL

18 - 150 years: 1.6 - 2.6mg/dL

Rejection Due To

Unlabeled, mislabeled, wrong tube type, QNS, hemolysis.

Report Available

Same day / 1 day

Clinical Significance

Magnesium is an essential nutrient which is involved in many biochemical functions. It has a structural role in nucleic acids and ribosomal particles, required as an activator for many enzymes and has a role in energy producing oxidative phosphorylation.

The normal body contains between 21 – 28 grams magnesium, more than 50% of which is complexed with Ca++ and phosphate in bone. Only approximately 1% of the total magnesium is found in the extracellular fluid; hence, it tends to enter and leave cells under the same conditions as K+. Approximately 35% of plasma Mg++ is protein-bound, mainly to albumin, and therefore changes in albumin concentration may affect Mg++.

Hypomagnesemia results in the impairment of neuromuscular function and may develop in severe prolonged diarrhea, malabsorption syndromes, hyperaldosteronism, and diuretic therapy.

Hypermagnesemia is seen in renal glomerular failure and diabetic coma.

Method Name




Day(s) Performed