Test Overview

Test Methodology

Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)

Test Usage

Therapeutic drug monitoring.

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

6 - 11 days

Soft Order Code





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Laboratory Reference

Mayo FHAL (90119) (MedTox 125)

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Specimen Requirements

Offsite Collection Instructions

Collect blood in 7 ml red or green top tube; do not use SST tube. Centrifuge, aliquot serum or plasma into plastic vial and store at room temperature or refrigerate.

Rejection Criteria

SST or PST tube not acceptable.


Yellow Top Tube
Red Top Tube

Normal Volume

2 ml serum or plasma

Minimum Volume

0.5 ml serum or plasma

Additional Information

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

Billing Information

Fee Codes

CPT Code


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