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Test Mnemonic:


Specimen Requirements:

7 mL of whole blood; protect from light and refrigerate. Mix well but gently before processing. Determine and record the hematocrit value. Aliquot the sample to small plastic tubes and seal tightly for storage. These are immediately placed in the freezer in the horizontal position to prevent separation of cells and plasma by gravity, or flash frozen using acetone-dry ice or liquid nitrogen.

Test Included:

Reflex if elevated: proportions of metal-free protoporphyrin and zinc protoporphyrin. Special request: pattern of individual porphyrins by HPLC.


Routine venipuncture.


Green-top tube (heparin).

Minimum Volume:

0.5 mL


Protect from light and refrigerate. See Shipping Instructions for more details.

Specimen Preparation:

Whole blood. 


Stable if light protected and refrigerated.

Causes for Rejection:

Sample not protected from light and not refrigerated will not be rejected, but their condition on arrival will be recorded in the results report.

Reference Range:

20 - 80 micrograms/dL

Turnaround Time:

Routine, test is performed weekly. 


Solvent extraction and fluorometry. 


Samples are accepted 24 hours per day at Sample Management, 7.412 CSW or from 8 AM - 5 PM, Monday - Friday at 3.102 Ewing Hall, 700 Harborside Drive, Galveston, TX; Phone (409) 772-9103 or 4661.


Porphyria Laboratory.


Erythrocyte protoporphyrin, total erythrocyte protoporphyrin, total erythrocyte porphyrins.

Clinical Indication:

A screening test for erythropoietic protoporphyria (EPP) and other protoporphyrias with the same phenotype, which cause acute nonblistering photosensitivity. 

Patient Preparation :

Not applicable.

CPT 4 Code:



Call Porphyria Laboratory at (409) 772-9103 or 4661 if any questions.

When ordering tests for which Medicare or Medicaid reimbursement will be sought, physicians should only order tests that are medically necessary for the diagnosis or treatment of the patient. Components of the organ or disease panels may be ordered individually. The diagnostic information must substantiate all tests ordered and must be in the form of an ICD-10 code or its verbal equivalent.
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