Days Set Up
Analytic Time

5 - 11 days

MiChart Code
Mercaptopurine (Imuran), Level
Soft Order Code

Test Updated:


6 Mercaptopurine (6 MP)
Mercaptopurine (6-MP) Level

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All specimens should be accompanied by a requisition.

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MLabs provides all the supplies necessary for the collection of specimens.

Test FAQ

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Test Overview

Test Methodology

High Performance Liquid Chromatography (HPLC)

Test Usage

Therapeutic drug monitoring of Mercaptopurine (6-MP) (Purinethol) or Azathioprine (Imuran) (measured as 6-Mercaptopurine).

Reference Range

Therapeutic and toxic ranges have not been established. Usual therapeutic doses of either mercaptopurine or azathioprine produce 6-mercaptopurine serum concentrations of less than 1000 ng/mL.

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

Specimen Requirements

Collection Offsite

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

Yellow Top Tube
Red Top Tube
Normal Volume
2 mL serum or plasma
Minimum Volume
0.3 mL serum or plasma

Billing Information

CPT Code
Pro Fee Code

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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.