Test Code SEROTM Serotonin, Serum
Additional Codes
MAYO: SER
EPIC: LAB121
Reporting Name
Serotonin, SUseful For
In conjunction with, or as an alternative to first-order test in the differential diagnosis of isolated symptoms suggestive of carcinoid syndrome, in particular flushing (5-HIAA or serum chromogranin A measurements are first-line tests)
Second-order test in the follow-up of patients with known or treated carcinoid tumors in serum specimens
Performing Laboratory

Specimen Type
SerumAdditional Testing Requirements
First-line testing for the diagnosis of carcinoid tumors with symptoms suggestive of carcinoid syndrome consists of urinary serotonin (SERU / Serotonin, 24 Hour, Urine), urinary 5-HIAA (HIAA / 5-Hydroxyindoleacetic Acid [5-HIAA], 24 Hour, Urine), and serum chromogranin A (CGAK / Chromogranin A, Serum).
Specimen Required
Patient Preparation: Patient should be off of medications that may affect serotonin concentrations including lithium, monoamine oxidase inhibitors, methyldopa, morphine, and reserpine.
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 2.5 mL
Collection Instructions: Centrifuge as soon as blood has clotted and aliquot into plastic vial.
Specimen Minimum Volume
1.1 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 21 days | |
Frozen | 90 days | ||
Ambient | 4 days |
Reference Values
≤230 ng/mL
Day(s) and Time(s) Performed
Monday, Wednesday, Friday; 10 a.m.
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
84260
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
SER | Serotonin, S | 27057-9 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
84395 | Serotonin, S | 27057-9 |
Reject Due To
Gross hemolysis | OK |
Gross lipemia | OK |
Gross icterus | OK |
Method Name
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)