Test Overview

Test Methodology


Reference Range*

5 - 25 ng/mL

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

Test Details

Days Test Performed


Analytic Time

5 - 7 days

Soft Order Code




Laboratory Reference

Mayo FBENZ (90092) (MedTox 894)

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Specimen Requirements

Offsite Collection Instructions

Collect trough specimen in a green top or red top tube; do not use SST tube. Centrifuge, aliquot plasma or serum into a plastic vial and refrigerate.

Rejection Criteria

SST or PST tube not acceptable.


Yellow Top Tube
Red Top Tube

Normal Volume

2 mL plasma or serum

Minimum Volume

0.3 mL plasma or serum

Additional Information

Test sent to Mayo Medical Laboratories; performed by MedTox Laboratories.

Billing Information

Fee Codes

CPT Code


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