Porphyrins, Fractionated, Quantitative, Random Urine
Use
This test is used to diagnose porphyria cutanea tarda, hereditary coproporphyria, and variegate porphyria. It assesses porphyrin levels and patterns, aiding in the evaluation of metabolic dysfunction, unexplained neurologic symptoms, photosensitivity, and disorders of heme biosynthesis.
Special Instructions
Collect a random urine specimen; random collection is preferred over 24‑hour. The specimen must be protected from ultraviolet light (use amber container or wrap in foil). Addition of sodium carbonate (5 g per 100 mL urine) is preferred but not required. Random urine should be refrigerated and protected from light during collection.
Limitations
Since this is a laboratory‑developed test, it has not been cleared or approved by the U.S. Food and Drug Administration, though its analytical performance characteristics have been internally determined by Quest Diagnostics. Degradation of analytes may occur if the specimen is exposed to ultraviolet light or if pH is < 4.0, potentially leading to inaccurate results. Repeat testing may be canceled if the test was previously performed.
Methodology
NGS
Biomarkers
Result Turnaround Time
5-7 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
Not provided
Minimum Volume
1.5 mL
Container
Amber transport tube or foil‑wrapped container
Collection Instructions
Transfer 2 mL aliquot from well‑mixed random urine to amber tube (preferred), or protect container from light with foil.
Storage Instructions
Refrigerated during transport.
Causes for Rejection
Received at room temperature; samples not protected from light; samples with pH < 4.0
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Unacceptable |
| Refrigerated | 7 days |
| Frozen | 30 days |