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HelpTest Code MG-24H Magnesium, Urine 24 hr
Useful For
This test is useful in assessing kidney function.
Synonyms/Keywords
Urine Magnesium
Specimen Requirements
| Fasting Required | Specimen Type | Preferred Container/Tube | Acceptable Container/Tube | Specimen Volume | Specimen Minimum Volume (allows for 1 repeat) |
Pediatric Minimum Volume (no repeat) |
|---|---|---|---|---|---|---|
| No | Urine, 24 hour | 24 hr urine jug with 7.0 g sulfamic acid | 24 hr urine jug with 20 mL 6N HCL or 25 mL 33% acetic acid | 10 mL aliquot of a well mixed 24 hr urine | 5 mL aliquot | 2 mL aliquot |
Collection/Processing Instructions
Indicate collection dates and times. Total volume must be measured, recorded and included with the test request.
If uric acid is also ordered, no preservative is needed, but keep specimen refrigerated during patient collection as well as during transport to receiving facility. Prepare 2 aliquots, adjusting pH of magnesium aliquot to 5 or less (using 6N hydrochloric acid. Adjust the pH of the second (uric acid) aliquot to 7.5-8.5 using 20% sodium hydroxide. Alternately, use Marshfield preservative containing aliquot tubes which provide automatic pH adjustment.
After measuring the total volume, create an aliquot and send the remaining urine in the collection jug to Marshfield; send both the aliquot and remaining urine in the collection jug. If a location is not able to measure the total volume, send the urine collection jug without making an aliquot.
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Refrigerate | 2 weeks |
Rejection Criteria
Specimens without preservative during collection (refrigeration or acid preservative)
Reference Range Information
| Performing Location | Reference Range |
|---|---|
| Marshfield |
Male: 42 - 182 mg/24 hours Female: 43 - 155 mg/24 hours |
Marshfield Labs Performing Department
Marshfield Labs Chemistry
Performing Information
| Performing Location | Day(s) Test Performed | Analytical Time | Methodology/Instrumentation |
|---|---|---|---|
| Marshfield | Monday through Sunday | Less than 2 hours | Xylidyl Blue Endpoint Assay/ Beckman AU |
CPT Codes
| CPT | Modifier (if needed) |
Quantity | Description | Comments |
|---|---|---|---|---|
| 83735 |
Outreach CPT Codes
| CPT | Modifier (if needed) |
Quantity | Description | Comments |
|---|---|---|---|---|
| 83735 |
Ordering Applications
| Ordering Application | Description |
|---|---|
| Cerner | Magnesium Level 24 Hour Urine |