URIC ACID - (U)
Test Code: UAU
Uric acid is the final product of purine metabolism. Urine uric acid excretion is used in the assessment and management of patients with kidney stones, particularly uric acid stones.
Collect 24 h urine without preservative. Refrigerate until analysis. Uric acid cannot be performed on the same 24h collection as tests requiring pH adjustment to ≤2 (Calcium Oxalate, Phosphate, HVA, VMA, 5-HIAA).
Random urines acceptable ONLY for pediatric endocrinology, pediatric nephrology and pediatric urology.
Urine: 24.0 hrs
Pediatric Urine: 24.0 hrs
An entire 24 hr urine collection is required. Please see patient collection brochure (PB110-50-01) for urine collection procedure.
Stability 4 days at room temperature (when NaOH added to collection)
Urine: 3.0 mL
24h collection: Measure and record volume; save an aliquot of urine for urine creatinine and then pH the remaining entire 24h collection to > 8.0 with 1M NaOH. Send aliquots (3mL) to the referral lab. Refrigerate until analysis.
Random collection: save an aliquot of urine for urine creatinine and then add NaOH to the remaining random urine sample to pH>8.
Send aliquots to the referral lab. Refrigerate until analysis.
24 h: 1.5 - 4.5 mmol/d (mmol/d x 0.17 = mg/d)
Random: < 12 mo: < 1.5 mmol/mmol creatinine
1 - 3 y: < 1.3
3 - 5 y: < 1.0
5 - 10 y: < 0.6
> 10 y: < 0.4
24hr Urine: Weekdays.....Random Urine: Weekdays for pediatric endocrinology, pediatric nephrology & pediatric urology.
See SOP 110-50-01, JA110-50-01A, JA110-50-01B.