HOMOCYSTEINE, QUANTITATIVE, URINE

Specimen Required
Patient Preparation: Patient needs to abstain from ingesting Vitamin C for 48 hours prior to collection. Collect 24 hour urine, refrigerate during collection. Mix well and send 5.0 mL aliquots unpreserved urine (3.0 mL minimum) frozen in screw-capped plastic urine containers. Record total volume on requisition and specimen label.

Alternate Specimen
Random urine

Rejection Criteria
pH <5 or >8 specimens with acid preservative. Large amounts of blood or hemoglobin can interfere with quantitation.

Methodology
Spectrophotometry

Stability
Room Temperature: Unacceptable; Refrigerated: 24 hours; Frozen: 1 month

Reference Range
0-32 mg/d   Homocystine, Urine  
0-53 mg/g CRT   Homocystine per gram of creatinine  
By report   Creatinine  

Performed
Monday

Turnaround Time7-10 days
Test CodeUHOMC
CPT-4 Code (s)
82131
LOINC Codes
Total volume   19153-6  
Homocystine mg/day   6884-1  
Creatinine per 24h   2162-6  
Homocystine mg/g Crt   13759-6  
Creatinine per volume   2161-8  
Hours collected    30211-7  
Homocystine mg/L   2431-5  

Warde
Medical
Laboratory