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Test Code XMAGU Magnesium, 24 Hour, Urine

Useful For

Assessing the cause of abnormal serum magnesium concentrations

 

Determining whether nutritional magnesium loads are adequate

 

Calculating urinary calcium oxalate and calcium phosphate supersaturation and assessing kidney stone risk

Method Name

Colorimetric Endpoint Assay

Reporting Name

Magnesium, 24 Hr, U

Specimen Type

Urine


Specimen Required


Collection Container/Tube: 24-hour graduated urine container with no metal cap or glued insert

Submission Container/Tube: Plastic, 5-mL tube (T465) or a clean, plastic urine container with no metal cap or glued insert

Specimen Volume: 4 mL

Collection Instructions:

1. Collect urine for 24 hours.

2. Refrigerate specimen within 4 hours of completion of 24-hour collection.

Additional Information:

1. 24-Hour volume is required.

2. See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens in Special Instructions for multiple collections.


Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated (preferred) 14 days
  Frozen  14 days
  Ambient  72 hours

Reference Values

51-269 mg/24 hr

Reference values have not been established for patients <18 years and >83 years of age.

Reference values apply to 24-hour collections.

Day(s) and Time(s) Performed

Monday through Sunday; Continuously

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test has been modified from the manufacturer’s instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

83735

LOINC Code Information

Test ID Test Order Name Order LOINC Value
MAGU Magnesium, 24 Hr, U In Process

 

Result ID Test Result Name Result LOINC Value
MG24 Magnesium, 24 Hr, U In Process
TM115 Collection Duration 13362-9
VL111 Urine Volume 3167-4
MGCN Magnesium Concentration In Process

Urine Preservative Collection Options

Ambient

Yes

Refrigerated

Preferred

Frozen

Yes

6N HCl

Yes

50% Acetic Acid

Yes

Na2CO3

No

Toluene

Yes

6N HNO3

Yes

Boric Acid

Yes

Thymol

Yes