Test ID: PQNU
Porphyrins, Quantitative, Urine
Specimen Type 
Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Container/Tube: Amber, 60-mL urine bottle (Supply T596)
Specimen Volume: 20-50 mL
Collection Instructions:
1. Patient should abstain from alcohol for 24 hours prior to, as well as during, collection.
2. Collect a 24-hour urine specimen.
3. Add 5 g of sodium carbonate (Supply T272) as preservative at start of collection. This preservative is intended to achieve a pH of >7. Do not substitute sodium bicarbonate for sodium carbonate.
4. The container should be refrigerated and protected from light as much as possible during collection.
5. Protect specimen from light.
Additional Information:
1. 24-Hour volume is required.
2. Collection date and time should be documented upon completion of the 24-hour collection.
3. Include a list of medications the patient is currently taking.
4. The pH will generally fall between 7 and 10 if the proper preservative (5 g sodium carbonate) was added to the container before the collection was started.
5. See Urine Preservatives in Special Instructions for multiple collections.
Forms: If not ordering electronically, submit a Biochemical Genetics Request Form (Supply T439) with the specimen.
Urine Preservative Collection Options
| Ambient | No |
| Refrigerate | No |
| Frozen | No |
| 6N HCl | No |
| 50% Acetic Acid | No |
| Na2CO3 | Required** |
| Toluene | No |
| 6N HNO3 | No |
| Boric Acid | No |
| Thymol | No |
| **Protect specimen from light. | |
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | NA |
| Lipemia | NA |
| Icterus | NA |
| Other | Specimen not protected from light, pH <5.0 |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Frozen | 7 days |
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