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.

Test Limitations

Medications that may affect serotonin concentrations include lithium, MAO inhibitors, methyldopa, morphine, and reserpine.

Test Details
Days Set Up
Monday, Wednesday, Friday
Analytic Time

2 - 8 days

Soft Order Code
MiChart Code
  • 5-Hydroxytryptamine
  • 5-hydroxy-tryptamine
  • Hydroxytryptamine, 5-
  • SERO
Reference Laboratory
Mayo SERWB (84373)
Special Testing
Specimen Requirements
Collection Instructions

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.
Additional Information

The preferred sample for measurement of serotonin includes all or most of the platelets (i.e., whole blood) or serum from completely clotted specimens. Serotonin- or tryptophan-rich foods (avocados, bananas, plums, walnuts, pineapple, eggplant, plantain, tomatoes, hickory nuts, kiwi, dates, grapefruit, cantaloupe, and honeydew melon) do not contribute significantly to serum or blood serotonin measurements, but can elevate platelet-poor plasma serotonin, urinary serotonin, and urinary 5-HIAA levels markedly (up to 10-fold). Test sent to Mayo Medical Laboratories.

CPT Code
Fee Code