Days Set Up
Monday, Wednesday, Friday
Analytic Time

2 - 8 days

MiChart Code
Soft Order Code

Test Updated:


Hydroxytryptamine, 5-

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Find a Requisition

All specimens should be accompanied by a requisition.

Submitting Specimens

Learn about how to properly label and where to ship specimens.

Order Kits and Supplies

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

Test FAQ

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Test Overview

Test Methodology

Liquid Chromatography Tandem Mass Spectrometry.

Test Usage

In conjunction or as an alternative to 5-HIAA or serum chromogranin A measurements as a first line test in the diagnosis of carcinoid syndrome.

Reference Range

<= 330 ng/mL

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

Specimen Requirements

Collection Onsite

Collect specimen in a lavender top tube.

Collection Offsite

Collect specimen in a lavender top tube. Transfer 2.5 mL of whole blood into Serotonin Whole Blood Transport tube (contains 20 mg ascorbic acid), mix well and freeze immediately. Do not over or under fill tubes.

Normal Volume
2.5 mL EDTA whole blood.
Minimum Volume
1.5 mL EDTA whole blood.

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.