Magnesium
Label Mnemonic: MG
Epic code: LAB103
Order form: Laboratory Requisition
Supply order: Supply Order Form
Billing: Billing Policies
CPT code: 83735
Specimen(s):
Plasma
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
Minimum:
3 mL whole blood in light green top tube or ONE Microtainer® for pediatric patients.
Rejection Criteria:
Avoid hemolysis
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
1.5-2.9 mg/dL

Critical value: <1.0 mg/dL and >4.7 mg/dL
Comments:
Refer to BD Microtainer® Tubes product sheet for detailed sample collection instructions.

Avoid hemolysis.

Please print, complete and submit the Advance Beneficiary Notice (ABN) along with the Laboratory Requisition before shipping the specimen.
Test Limitations:
Criterion: Recovery within plus or minus 10% of initial values.

Plasma
Icterus: No significant interference up to an I index of 60. 

Hemolysis: No significant interference up to a H index of 800. 

Lipemia (Intralipid): No significant interference up to an L index of 
2000 (approximate triglycerides concentration: 4000 mg/dL). There is 
poor correlation between turbidity and triglycerides concentration. 

In-vitro tests were performed on 34 commonly used pharmaceuticals. 

No interference with the assay was found.

Reference:
Glick MR, Ryder KW, Jackson SA. Graphical Comparisons of Interferences 
in Clinical Chemistry Instrumentation. Clin Chem 1986;32:470-474.
Methodology:
Colorimetric endpoint
Sample Processing:
Centrifuge at a speed and time necessary to get barrier separation of plasma/serum and cells within 1 hour of collection. Send specimen in original tube. Do Not transfer to another tube.
Each sample must be labeled with at least TWO full patient identifiers (First/Last Name & DOB are sufficient for non-UIHC affiliated clients) to avoid sample rejection/delays.
Sample Storage:
Refrigerate.
All sample storage requirements are intended for delivery to UIHC within 24 hours of collection for testing. If samples won't arrive in this time period, please call the UIHC Core Lab for alternative storage/shipping instructions (319-356-3527).
Transport Instructions:
Place labeled specimen into zip-lock type biohazard bag; seal bag.
Place completed requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.
CPT Code:
83735
 
See Additional Information:
Chemistry Critical Lab Values