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HelpOrder Code LAB1276 Cystinuria Profile, Quantitative, 24 Hour, Urine
Additional Codes
Mayo Test Code: CYSQN
Reporting Name
Cystinuria Profile, QN, 24 hourUseful For
Diagnosis of cystinuria using 24-hour urine collections
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
UrineNecessary Information
1. 24-Hour volume (in milliliters) is required.
2. Patient's age is required.
3. Include family history, clinical condition (asymptomatic or acute episode), diet, and drug therapy information.
Specimen Required
-Urine Tubes, 10 mL (T068)
-Diazolidinyl Urea (Germall) 5.0 mL (T822)
Specimen Volume: 5 mL
Collection Instructions:
1. Collect before intravenous pyelogram.
2. Add 5 g of diazolidinyl urea (Germall) as preservative at start of collection. If preservative is not available, refrigerate during collection.
3. Collect urine for 24 hours.
4. Mix well before taking 5-mL aliquot.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.
Specimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Frozen (preferred) | 70 days | |
| Refrigerated | 14 days |
Special Instructions
Reference Values
Cystine
3-15 years: ≤53 mcmol/24 h
≥16 years: ≤115 mcmol/24 h
Lysine
3-15 years: ≤140 mcmol/24 h
≥16 years: ≤290 mcmol/24 h
Ornithine
3-15 years: ≤16 mcmol/24 h
≥16 years: ≤70 mcmol/24 h
Arginine
3-15 years: ≤25 mcmol/24 h
≥16 years: ≤64 mcmol/24 h
Conversion Formulas:
Result in mcmol/24 hours x 0.24 =result in mg/24 h
Result in mg/24 hours x 4.17 =result in mcmol/24 h
Day(s) Performed
Monday through Friday
CPT Code Information
82136
Genetics Test Information
This test provides a biochemical diagnosis of cystinuria through the measurement of cystine, lysine, ornithine, and arginine.
Method Description
Quantitative analysis of amino acids is performed by liquid chromatography tandem mass spectrometry. Patient samples are combined with isotopically labeled internal standard. Following protein precipitation, the supernatant is subjected to hydrophilic-interaction liquid chromatography for the separation of isomers with MS/MS detection of the underivatized amino acids.(Unpublished Mayo method)
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Forms
If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.