8 hours
Test Updated:
Looking to order a test?
We’ve provided helpful links to make ordering easy.
Find a RequisitionAll specimens should be accompanied by a requisition.
Submitting SpecimensLearn about how to properly label and where to ship specimens.
Order Kits and SuppliesMLabs provides all the supplies necessary for the collection of specimens.
Test FAQVisit our provider FAQ and learn about common questions to ordering tests.
Test Overview
Potentiometric (ISE)
Renal function, electrolyte balance studies
43 - 217 mEq/24 hrs (43-217 mMol/24 hrs). Random urine collections are reported in units of mmol/L, for which reference values are not established.
* Reference ranges may change over time. Please refer to the original patient report when evaluating results.
Specimen Requirements
Random or 24 hour urine. Container MUST be labeled with date and time collection started and finished. Instruct the patient to void at 8:00am and discard the specimen. Then collect all urine including the final specimen voided at the end of the 24 hour collection period, i.e., 8:00am the next morning. Screw the lid on securely. Transport the specimen promptly to the laboratory. Refrigerate during collection. Any test requiring a 24 hour urine collection with no preservative may also be run on this specimen.
Collect 24 hour urine specimen with no preservative. Aliquot 5 mL into a plastic urine container and refrigerate. Record total 24 hour urine volume and collection dates/times on request form. Random urine also acceptable.