Cleveland HeartLab M, Test

CPT Code: 83735
Order Code: C150
ABN Requirement:  No
Synonyms: Mg; Mag
Specimen: Serum
Volume: 0.5 mL
Minimum Volume: 0.2 mL
Container: Gel-barrier tube (SST, Tiger Top)


  1. Collect and label sample according to standard protocols.
  2. Gently invert tube 5 times immediately after draw. DO NOT SHAKE.
  3. Allow blood to clot 30 minutes.
  4. Centrifuge at 1300 rcf for 10 minutes.

Transport: Store serum at 2°C to 8°C after collection and ship the same day per packaging instructions provided with the Cleveland HeartLab, Inc. shipping box.


Ambient (15-25°C): 7 days
Refrigerated (2-8°C): 7 days
Frozen (-20°C): 1 year
Deep Frozen (-70°C): 1 year

Causes for Rejection: Specimens other than serum; improper labeling; samples not stored properly; samples older than stability limits

Methodology: Enzymatic Colorimetric Assay

Turn Around Time: 1 to 3 days

Reference Range:

Age mg/dL
All Ages 1.7-2.6


Critical Value:

Age Critical Low mg/dL Critical High mg/dL
All Ages ≤1.0 ≥4.8


Intended Use: Magnesium testing is used for the evaluation of kidney disorders, electrolyte balance and hypokalemia.

Limitations: In very rare cases gammopathy may cause unreliable results.