Test Overview
Test Methodology


Test Usage

Preferred test for analysis of erythrocyte porphyrins. Establishing a biochemical diagnosis of erythropoietic protoporphyria, and X-linked dominant protoporphyria.

Reference Range *

PORPHYRINS, TOTAL, RBC: <80 mcg/dL packed cells; FREE PROTOPORPHYRIN: <20 mcg/dL packed cells; ZINC-COMPLEXED PROTOPORPHYRIN: <60 mcg/dL packed cells.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Details
Days Set Up
Monday, Wednesday, Friday
Analytic Time

5 - 9 days

Soft Order Code
  • Porphyrin Evaluation, Washed Erythrocytes
Reference Laboratory
Special Testing
Specimen Requirements
Collection Instructions

Patient should abstain from alcohol for 24 hours prior to specimen collection. Collect blood in a green top tube. Place on wet ice immediately. Process as follows:
a. Immediately place specimen on wet ice.
b. Transfer entire specimen to a 12-mL graduated centrifuge tube.
c. Centrifuge specimen for 10 minutes at 2,000 rpm.
d. Record volume of packed cells and the total volume of the specimen.
e. Discard supernatant plasma.
f. Wash packed erythrocytes 2 times by resuspension of at least an equal amount of cold 0.9% saline, mix, and centrifuge for 5 minutes at 2,000 rpm, discarding supernatant after each washing.
g. Resuspend packed cells to the original total volume with 0.9% saline. Invert specimen gently to mix.
h.Transfer washed erythrocytes into a plastic vial and freeze.
Volume of packed cells and total volume of erythrocyte suspension (red cells + saline) are required and must be sent with specimen. Include a list of medications the patient is currently taking.

Special Handling

Place on ice immediately following collection. See below for processing instructions. (Pass to Chem along with Mayo instructions)

Alternate Specimen
Dark blue top (metal free heparin) or green top (lithium heparin).
Normal Volume
5 mL washed erythrocyte suspension
Minimum Volume
1 mL washed erythrocyte suspension
Additional Information

Test sent to Mayo Medical Laboratories.

CPT Code