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Tryptophan-Kynurenine Ratio Targeted Panel

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Tryptophan/Kynurenine Ratio Targeted Panel

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About the Kynurenine Pathway

The kynurenine pathway is a metabolic pathway leading to the production of nicotinamide adenine dinucleotide (NAD+) from the enzymatic conversion of tryptophan. Immune activation leads to the formation of kynurenine with a corresponding loss of tryptophan. The kynurenine/tryptophan ratio has been used to reflect the activity of the tryptophan-degrading enzyme indoleamine 2,3-dioxygenase (IDO) in cellular inflammatory responses related to symptoms of depression, schizophrenia, and other neurological diseases.

Metabolomics reveals biological insights otherwise unseen. For a successful metabolomics study, both small molecule discovery and the ability to dig deeper into specific biomarkers of interest are needed to uncover actionable insights that propel new therapeutic developments. A specific combination of liquid chromatography-mass spectrometry (LC-MS) technology and expertise is required to identify these biomarkers of interest and develop assays that are sensitive enough to explore them fully.

At Metabolon, we understand the crucial role that the kynurenine pathway plays in inflammation and neurological diseases, and we’ve established best-in-class expertise for the detection of its intermediates. This panel focuses on specific metabolites and their metabolic pathways and can be used to track biomarkers and enhance biological understanding across preclinical and clinical research.

Tryptophan/Kynurenine Ratio Targeted Panel Details

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Kynurenine/Tryptophan Ratio Assay Plasma/Serum
Tryptophan 500 ng/mL
Kynurenine 50.0 ng/mL
Analysis Method and Instrumentation:
LC-MS/MS (Agilent 1290 UHPLC/Sciex QTrap 5500)
Sample Type and Required Amounts
Sample Type Sample Requirements
Plasma/Serum ≥ 150 µL

Others on request

Disclaimer: This method is for Research Use Only and is not to be used for diagnostic purposes. The sample requirements listed are for this specific panel. Additional samples will be required if running multiple panels.

Delivering Absolute Quantification for Research and Biomarker Analysis

Our readily available or custom developed quantitative assays help you achieve your research and biomarker validation objectives with precise and fully validated methods. Our targeted assays and panels cover >1,000 metabolites and lipids across a wide range of biochemical classes, metabolic pathways, and physiological processes, and they can be customized to best fit any application.

Tryptophan/Kynurenine Ratio Targeted Panel Applications


The importance of inflammation in the development of multiple diseases- and health-related conditions including neurodegeneration, diabetes, cardiovascular disease, cancer, and inflammatory bowel disease is undisputed. Metabolomics can inform on inflammatory processes by providing a readout of the small molecules of an organism, tissue, biofluid, etc. This allows for direct molecular phenotyping of inflammation beyond the standard protein markers of typical assays. Metabolon offers several targeted assays, including oxysterols, fatty acids, kynurenine/tryptophan, and a range of others (central carbon, glucose tolerance, branched-chain amino acids, β-hydroxybutyrate) that can also inform on overall cardiovascular health that is often linked with inflammatory processes.

gut health

Gut Health

Gut health is important for overall health. Alterations of the gut microflora can cause several types of gastrointestinal disorders (including irritable bowel syndrome and viral hepatitis. In addition, gut microflora has also been implicated to play a role in autoimmune disease, skin disorders, as well as in diabetes and obesity. The unique ability for metabolomics to identify microbial metabolites and how they regulate pathways in the host makes the technology a valuable tool for understanding gastrointestinal and other metabolic disorders.


Metabolomics provides valuable insight into the realm of brain science. Through dynamic bidirectional communication along the “gut-brain axis,” gut microbes collaborate with their hosts to regulate the development and function of the nervous system. For instance, in epilepsy, it is well-established that a low-carbohydrate, high-fat ketogenic diet (KD) can help treat refractory epilepsy, which affects more than a third of epileptic patients who don’t respond to existing anticonvulsive drugs. What scientists haven’t understood until recently is how this kind of diet translates to brain activity. The answer for this aspect of epilepsy lies in the gut microbiome. There are many other neurological disorders like Alzheimer’s disease, ALS, Parkinson’s disease and more. While so much remains to be understood about brain science, we do know that metabolomics is uniquely poised to understand the brain because of the ability of metabolites, small molecules, to cross the blood-brain barrier providing unique insights.


Dysregulated metabolism is essential for the growth and proliferation of individual cancer cells, but the physiology of the patient is as much a part of the equation as the tumor. Metabolomics can both identify cancer-specific drug targets and assess the patient’s phenotype more broadly, addressing key questions such as: Who will respond to the therapy? How can we expand the pool of responders? How can we predict adverse events? Overall, metabolomics informs decision-making and positions development programs for success by providing a functional readout of the molecular phenotype.

Personal Care & Cosmetics

Metabolon’s technology can provide a comprehensive survey of the skin metabolome and microbiome from a range of non-invasive skin sampling options, including our proprietary sample preparation process that allows subjects to provide samples using commercially available tape strips. In addition to our global Precision Metabolomics platform, we can quantitatively measure hundreds of lipid analytes on our pre-existing skin lipid panels. With the ability to capture biomarkers of wound repair, UV exposure, hydration, environmental exposures, and more, our proprietary platform has helped researchers understand skin conditions as diverse as dandruff, atopic dermatitis, psoriasis, acne, and aging.
Personal Care & Cosmetics


Recognized for our cutting-edge approach to metabolomics, Metabolon has been a valued resource for COVID-19 researchers worldwide. Our actionable metabolomic insights have fueled pivotal and high-profile studies like the National Institute of Allergy and Infectious Diseases (NIAID) IMPACC study research to improve understanding of high-risk patients and the Institute for Systems Biology research to improve understanding of high-risk patients. These and other metabolomics projects with actionable insights at Metabolon are helping get closer to the phenotype and pressing forward on COVID-19 answers.

Big Insights with Metabolon

Cited in over 3,000 publications, we help scientists and manufacturers gain greater insight into their studies through metabolomics. See how our approach can become a successful part of your workflow.

Contact Us

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Request a quote for our services, get more information on sample types and handling procedures, request a letter of support, or submit a question about how metabolomics can advance your research.

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