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HelpTest Code PQNU Porphyrins, Quantitative, 24 Hour, Urine
Ordering Guidance
This 24-hour urine test should be ordered when the specimen will not be received at Mayo Clinic Laboratories (MCL) within 72 hours. If the specimen will be received at MCL within 72 hours, order PQNRU / Porphyrins, Quantitative, Random, Urine.
Shipping Instructions
Ship specimen in amber container to protect from light.
Necessary Information
1. 24-Hour volume (in milliliters) is required.
2. Patient's sex is required.
3. Collection date and time should be documented upon completion of the 24-hour collection.
4. Include a list of medications the patient is currently taking.
Specimen Required
Patient Preparation: For the 24 hours before, as well as during, specimen collection, patient must not consume any alcohol.
Supplies:
-Urine Container - Amber, 60-mL (T596)
-Sodium Carbonate, 5 gram (T272)
Container/Tube: 60-mL Amber urine container
Specimen Volume: 20 to 50 mL
Collection Instructions:
1. Add 5 g of sodium carbonate as preservative at start of collection. This preservative is intended to achieve a pH above 7. Do not substitute sodium bicarbonate for sodium carbonate.
2. Collect a 24-hour urine specimen.
3. The container should be refrigerated and protected from light as much as possible during collection.
4. Record volume and duration.
5. Aliquot 20 to 50 mL into an amber container and freeze.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.
CMH COLLECTION: urine in urine jug. Keep refrigerated and protect from light during collection.
Specimen Minimum Volume
15 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Frozen | 7 days | LIGHT PROTECTED |
Useful For
Preferred screening test for congenital erythropoietic porphyria and porphyria cutanea tarda and during symptomatic periods for acute intermittent porphyria, hereditary coproporphyria, and variegate porphyria when specimen transport will be longer than 72 hours
This test is not useful for the diagnosis of conjugated or unconjugated hyperbilirubinemia syndromes such as Dubin Johnson syndrome or Rotor syndrome
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Day(s) Performed
Monday through Friday
Report Available
2 to 4 daysReporting Name
Porphyrins, QN, UReference Values
Uroporphyrins, Octa: ≤30 nmol/24 h
Heptacarboxylporphyrins: ≤9 nmol/24 h
Hexacarboxylporphyrins: ≤8 nmol/24 h
Pentacarboxylporphyrins: ≤10 nmol/24 h
Coproporphyrin, Tetra:
Males: ≤230 nmol/24 h
Females: ≤168 nmol/24 h
Porphobilinogen: ≤2.2 mcmol/24 h
Method Name
High-Performance Liquid Chromatography (HPLC) with Fluorometric Detection/Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
84110-Porphobilinogen, quantitative
84120-Porphyrins, quantitation and fractionation