Uroporphyrinogen decarboxylase, whole blood

Alphabetical Test listing

Uroporphyrinogen decarboxylase, whole blood-994

Uroporphyrinogen decarboxylase, whole blood
Erythrohepatic Uroporphyria (EHUP)
Hepatoerythropoietic Porphyria (HEP)
Porphyria Cutanea Tarda (PCT)

Preferred test for the confirmation of a diagnosis of porphyria cutanea tarda type II and hepatoerythropoietic porphyria.

  • Patient should abstain from alcohol for 24 hours.
    • Abstinence is essential for at least 24 hours as alcohol suppresses enzyme activity for 24 hours after ingestion.
Sodium heparin (Na hep) whole blood
4.0 mL
3.0 mL

Immediately following collection, mix sample thoroughly by gently inverting 8 - 10 times, to prevent clotting


Dk green Sodium heparin (Na hep), no gel

EDTA whole blood
Lithium heparin (Li hep) whole blood

Lavender (EDTA), 4mL

Dk green Lithium heparin (Li hep), no gel


Refrigerated (preferred) – 14 days

Ambient – 7 days

Frozen – NO

2 weeks

Gross hemolysis

Mayo Clinic Laboratories (UPGD): R-NX
Tu, Th
7 days

High-Performance Liquid Chromatography (HPLC)/Incubation of lysed erythrocytes


≥1.0 Relative units (RU) - normal

0.80 - 0.99 Relative units (RU) - indeterminate

<0.80 Relative units (RU) - indicative of PCT type II

Alcohol ingestion within 24 hours of specimen collection may lead to a false-positive result.