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Laboratory Medicine

Test catalogue

Magnesium (Mg)

Test Name

Magnesium (Mg)

Light Green Tube Specimen Type / Requirements

Container Type = Gold (SST) or Lt Green (PST)

Minimum Testing Volume = 0.5mL Serum or Plasma

Preferred Testing Volume = 1mL Serum or Plasma

Tube must fill to at least ½ or greater of its vacuum capacity

Specimen Handling

Collection Instructions: Serum or heparinized plasma collected with or without gel separator. Write your initials, date and time of collection on the collection label or requisition.

Special Instructions Separate serum or plasma from cells within 2 hours of collection

Rejection Criteria: Gross hemolysis, Unlabeled or Not Sufficient Quantity samples will be rejected.

Stability:Stable for 1 week separated from cells at room temperature, refrigerated for 1 week and frozen -15 to -20°C for 1 year.

Transportation:Send sample to core lab as soon as possible.

Reference Value

Age Normal Range Abnormality - Critical Units
0 up to 15 Days 0.83-1.65 < 0.40 or >2.50 mmol/L
15 Days up to 1 Years < 0.40 or >2.50 0.82-1.29 mmol/L
1 Years up to 19 Years 0.87-1.19 < 0.40 or >2.50 mmol/L
19 Years up to Unspecified 0.73-1.00 < 0.40 or >2.50 mmol/L

Test Code

LAB103

Methodology

Spectrophotometric (Colorimetric; Endpoint method)

Testing Location

SMH-Biochemistry

Other Information

Last Updated: August 18, 2026