Cystine, 24-Hour Urine [10947X]

For Specimen Integrity during Extreme Weather see the “Lockbox Usage in Extreme Weather” document at the top of this page.

Test Code

Alias/See Also

CPT Codes

Preferred Specimen
1.8 mL of a 24-hour urine collected in a 24-hour urine container

Minimum Volume
0.6 mL

Do not use preservatives. Urine with a pH less than 2.0 will be rejected. Keep collection container refrigerated during 24-hour collection. Start collection after first morning void. Collect through first morning void of the next day. Take collection to the laboratory ASAP on the second day. The laboratory will mix sample well, measure total volume and remove an aliquot to send for testing. Freeze aliquot immediately.

Transport Temperature

Specimen Stability
Room temperature: Unacceptable
Refrigerated: 48 hours
Frozen: 60 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
pH <2.0 • IVP within 48 hours of collection

Chromatography/Mass Spectrometry

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule
Set up: Tues, Thurs a.m.; Report available: 4-10 days

Reference Range
  0-9 years 6-48 umol/24 hrs
  10-13 years 10-94umol/24 hrs
  14-17 years 17-102 umol/24 hrs
Adults 24-184 umol/24 hrs

Clinical Significance
Cystinuria is an autosomal recessive disease in which dibasic amino acids, including cystine, are excreted in excess. Cystine kidney stones account for approximately 1-3% of all kidney stones. Age of onset is often younger than with other types of kidney stones and the recurrence is approximately one-third.

Performing Laboratory
Quest Diagnostics Nichols Institute-San Juan Capistrano, CA
33608 Ortega Highway
San Juan Capistrano, CA 92675-2042

Last Updated: November 29, 2021

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.