Liquid Chromatography Tandem Mass Spectrometry
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.
Medications that may affect serotonin concentrations include lithium, MAO inhibitors, methyldopa, morphine, and reserpine.
4 - 9 days
- Hydroxytryptamine, 5-
- SEROTONIN, SERUM
Collect specimen in a red top or SST tube. Centrifuge as soon as blood has clotted, aliquot serum into a plastic vial within 30 minutes of collection and refrigerate.
Deliver to lab within 15 minutes or aliquot within 30 minutes. Spin as soon as blood has clotted.
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.