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HelpTest Code CTCR Citrate : Creatinine Ratio (NUHS)
Laboratory Code
LAB3041878
Specimen Requirements
Specimen Type: Random urine specimen without preservatives
Container/Tube: Sterile screw-capped container without preservatives
Volume: 100.0 mL
Minimum Volume: 20.0 mL urine
Collection Instructions: Collect mid-stream urine in preservative-free urine container. Unacidified urine.
Specimen Stability
| Specimen Type | Urine |
|---|---|
| Ambient | Send the sample to the laboratory immediately |
| Refrigerate | 4 days (preferred) |
| Frozen | 2 weeks |
Methodology
| Citrate | Enzymatic Colourimetric Assay |
|---|---|
| Creatinine | Enzymatic |
Days and Times Performed
Tuesday, TAT 2 - 8 days
Specimen Condition
| Haemolysis | Not applicable |
|---|---|
| Icterus | Not applicable |
| Lipaemia | Not applicable |
| Others | Not applicable |
Reference Interval
| Age | Male | Female |
|---|---|---|
| 2 – < 7 yrs | 27 – 86 mg/mmol | 33 – 98 mg/mmol |
| 7 – < 13 yrs | 16 – 62 mg/mmol | 30 – 78 mg/mmol |
| 13 – < 18 yrs | 10 – 38 mg/mmol | 24 – 69 mg/mmol |
Reference ranges provided are based on 5th to 50th percentile. Patients at risk of nephrolithiasis should ideally have urine citrate excretion ≥ 50th percentile.
Testing Laboratory
National University Hospital
Clinical Chemistry, 67724399
Useful For
Investigation of renal calculi
Service Code
0031152
LOINC Code Information
| Citrate, urine | 34266-7 |
|---|---|
| Creatinine, urine | 14683-7 |
| Citrate : Creatinine ratio | 29527-9 |
Update
Last updated 24/02/2025