Days Set Up
Varies; test performed every other week, on Friday.
Analytic Time

8 hours

MiChart Code
Citrate, 24 HR Urine
Soft Order Code

Test Updated:


Citric Acid

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Find a Requisition

All specimens should be accompanied by a requisition.

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MLabs provides all the supplies necessary for the collection of specimens.

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Test Overview

Test Methodology

Compound Enzyme Assay

Test Usage

Diagnosis of renal tubule acidosis and some forms of calcium-dependent kidney stones.

Reference Range

Normal adult: greater than 200 mg/24 hrs (> 1058 uMol/24 hrs)

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Specimen Requirements

Collection Onsite

24 hour urine. Instruct patient to void at 8:00am (or 8:00pm) 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 (or 8:00pm) the following day. SPECIMEN MUST BE KEPT ON ICE DURING THE COLLECTION. Transport promptly to the laboratory. Container must be labeled with date and time collection started and finished. Any test requiring 24 hour urine collection, collected in 50% glacial acetic acid, including urinary oxalate, may also be run on this specimen. Citruria may be seen in alkalinized patient's urine. Cause for Rejection: Specimen not kept chilled during collection.

Collection Offsite

Collect 24 hour urine specimen. Add 25 mL of 50% glacial acetic acid (15 mL for pediatric patients) to container prior to start of collection. Following collection, mix very well to dissolve any citrate crystals that may have formed, measure 24 hour urine volume, aliquot 20 mL into a plastic urine container and refrigerate. Record total 24 hour urine volume and collection dates/times on request form. Specimens with no preservative are also acceptable: send entire 24 hour collection to MLabs.

Normal Volume
20 mL aliquot of 24 hour urine collection
Minimum Volume
5 mL aliquot of 24 hour urine collection

Billing Information

CPT Code
Pro Fee Code

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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.