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Test Code I Mg Ionized Magnesium Level

Aliases

Magnesium, Ionized; Mg++

Patient Preparation

No special patient preparation required

Special Collection Instructions

Must be completed within 4 hours of specimen being opened

Collection Method

Venous collection

Minimum Volume

  • Adults: 0.8 ml
  • Pediatric: 0.5 ml

Container

Lt Green / Plasma Separator / Lithium Heparin

Preferred Specimen

Light Green Top (lithium heparin) plasma

Acceptable Specimens

Serum:

  • Gold Top SST
  •  
  • Red Top


Plasma:

 

  • Light Geen Top (lithium heparin)

 

Reference or Target Ranges

0.43 – 0.61 mmol/L

Reportable Units

mmol/L

Critical Value

<0.31 or >1.50 mmol/L

Reasons for Rejection

 

 

Hemolysis Threshold No gross hemolysis
Icterus Threshold No significant interference
Lipemia Threshold No significant interference
Other QNS, contaminated, improperly Labeled, improper specimen type, specimen past 4 hours after opening

 

 

Specimen Stability

 

 

Ambient 4 hours once opened and recapped
Refrigerated (4°C to 8°C) 24 hours unopened
Frozen(-40°C to 0°C) N/A

 

 

Performance Information

 

 

Days and Time Performed 24/7
Expected Turn Around Time Stat: 1 hour if at UH. Stat not available for WCH
Routine: 4 hours
Stat Availability Yes
Performing Bench UH Chemistry
Methodology/Method Description NOVA pHOX – Electrode calculation

 

 

Additional Information/Important Notes

We suggest not switching between serum and plasma samples for a single patient due to slight bias in sample types.

CPT Codes

83735