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Test Code
TMAO
Test Name
Trimethylamine N-Oxide
CPT Codes
82542
Expected Turnaround Time
6 days
Clinical Utility
Gut microbes live symbiotically within the human digestive tract and play important roles in host defense, immunity, and nutrient processing and absorption. The diverse community is unique to each person and influenced by both acute and chronic dietary exposures to various food sources. Nutrients such as phosphatidylcholine (also known as lecithin), choline, and L-carnitine are abundant in animal-derived products such as red meat, egg yolk and full-fat dairy products. When consumed, these nutrients are processed by gut bacteria resulting in the release of various metabolites including TMA (trimethylamine) into the blood. TMA is then transported to the liver where it is converted into TMAO (trimethylamine N-oxide) which has been shown to regulate various physiological processes involved in the development of atherosclerosis.
Specimen and Container Info

Specimen Type: Serum

  

Collection Container: Gold Top, Serum Separator

Alternate Collection Container: Red Top, Plain

Desired Specimen Volume: 1 mL
Collection Instructions
  1. Collect a gold top, serum separator tube via venipuncture.
Processing and Submission Instructions
  1. Separate serum from cells.
  2. Transfer 1 mL of serum to a clear aliquot tube (screw cap).
Patient Preparation

Patients should fast overnight and refrain from consuming fish or other seafood the day before the blood draw to avoid false elevations in TMAO.
Transport Instructions

Transport to the laboratory refrigerated. 
Stability Requirements

Room Temperature

5 days

Refrigerated

23 days

Frozen

193 days
Causes for Rejection
  • Hemolysis
Methodology
Liquid Chromatography-Tandem Mass Spectrometry
Reference Intervals

See patient report.
Reference Lab
Quest Diagnostics Nichols Institute
Testing Schedule
Routine, Monday - Saturday
The American Medical Association (AMA) Current Procedural Terminology (CPT) codes published by HNL Lab Medicine are guidelines and are intended for informational purposes only. CPT coding is the exclusive responsibility of the billing entity. View the Terms.
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