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Test ID: PQNU    
Porphyrins, Quantitative, 24 Hour, Urine

Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.

The following algorithms are available in Special Instructions: 

-Porphyria (Acute) Testing Algorithm

-Porphyria (Cutaneous) Testing Algorithm

Specimen Type Describes the specimen type needed for testing

Urine

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 (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 (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.

 

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.

15 mL

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 TypeTemperatureTime
UrineFrozen7 days

Key