Tryptophan is an essential amino acid that serves as a precursor for several biologically important molecules, including serotonin, melatonin, and niacin (vitamin B3). It is obtained through the diet and metabolized via two main pathways: the serotonin pathway and the kynurenine pathway. As a biomarker, tryptophan reflects nutritional status, amino acid metabolism, and the balance of serotonin and kynurenine production, linking it to neurological, immune, and metabolic processes. Its levels can be measured in plasma, serum, cerebrospinal fluid, or tissue using methods such as high-performance liquid chromatography (HPLC) or mass spectrometry.
In research, tryptophan is used to study neurotransmitter synthesis, mood regulation, immune function, and metabolic pathways. Altered tryptophan metabolism is investigated in models of depression, anxiety, neurodegenerative disorders, and chronic inflammation. Researchers often examine the ratio of kynurenine to tryptophan to assess the activity of indoleamine 2,3-dioxygenase (IDO), an enzyme induced by immune activation, providing insight into inflammation-related changes in tryptophan catabolism.
Clinically, tryptophan serves as a biomarker for nutritional status, mood disorders, and immune-related conditions. Low tryptophan levels can be associated with depression, sleep disturbances, or malnutrition, while altered tryptophan metabolism may indicate chronic inflammation, cancer, or infection. Monitoring tryptophan and its metabolites can guide dietary interventions, therapeutic strategies, and the assessment of serotonergic or immune system function, linking basic biochemical research with clinical diagnostics and treatment planning.
This product is manufactured in Germany by LDN.
| Size | 1 x 96 Well |
| Sensitivity | 1.2 µg/mL |
| Dynamic Range | 2.5 – 250 µg/mL |
| Incubation Time | Overnight |
| Sample Type | Urine, plasma, serum |
| Storage | 2-8°C |
| Alternative Names | L-tryptophan, α-amino-β-(indol-3-yl)propionic acid, or Trp |
