Lab Test

pH, Urine

Urine pH, pH, Urine by Meter

Test Codes



Please refer to the Specimen Collection Manual for instructions on 24 Hour Urine Collection:

Specimen Collection Criteria

Collect (preferred specimen): Random urine specimen in a screw-capped container (preferred) or other sterile collection cup. (Minimum: 0.2 mL)
Also acceptable: 24 hour or timed urine specimen with no preservatives.

  • Refer to the table of Urine Preservative Options when multiple tests are requested.
  • Keep 24 hour urine specimen iced or refrigerated during collection.
  • Include start and end dates and times for the collection period on the specimen container.
Urine Preservative Options
No Preservative
6N Hydrochloric Acid
Boric Acid (10g)
Sodium Carbonate
50% Acetic Acid

    Physician Office/Draw Specimen Preparation

    Maintain specimens capped (to prevent pH changes) and refrigerated (2-8°C or 36-46°F) prior to transport.

    Preparation for Courier Transport

    Transport: Random urine, or entire 24 hour or timed urine collection, refrigerated (2-8°C or 36-46°F).

    Rejection Criteria

    Specimens not collected and processed as indicated. 

    In-Lab Processing

    Keep specimen capped to prevent pH changes. Measure total volume of 24 hour or timed urine specimen. Record total volume and collection start and end dates and times in the LIS system. Aliquot a minimum of 10 mL from the well-mixed 24 hour or timed urine collection.


    Specimen Stability for Testing:

    Room temperature (20-26°C or 68-78.8°F): 4 hours
    Refrigerated (2-8°C or 36-46°F): 7 days
    Frozen (-20°C/-4°F or below): For longer storage.

    Specimen Storage in Department Prior to Disposal:

    Refrigerated (2-8°C or 36-46°F): 7 days (Royal Oak and Troy store an aliquot for 30 days.)


    Grosse Pointe Chemistry Laboratory
    Royal Oak Automated Chemistry Laboratory
    Troy Chemistry Laboratory (Pediatric Patients Only).


    Sunday – Saturday.
    Results available within 24 hours.

    Reference Range

    4.5 – 8.0.

    Test Methodology

    pH test strip.


    • Urine pH is a measure of the acidity/alkalinity of urine and by itself usually provides little useful information. Under normal conditions its value is influenced by the type of diet. Some diets (e.g., diets rich in meat) have more acid content than others (e.g., vegetarian diets).
    • Changes in urine pH may reflect systemic acid-base disorders. For example, the normal response during metabolic acidosis is a lowering of the urine pH to less than 5. If the pH is greater than 5, then a defect in urine acidification should be considered. A urine pH greater than 7 is suggestive of infection by a urea-splitting organism such as Proteus mirabilis.
    • Therapeutic interventions to either alkalinize or acidify the urine are necessary for some diseases. For example, some crystals have a propensity to form in alkaline urine, while others form in relative acidic urine, and changing the pH may reduce stone formation.

    CPT Codes



    Last Updated


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    This directory currently reflects information only for specimens collected and/or processed at the
    Farmington Hills, Grosse Pointe, Royal Oak, and Troy campuses.