AhR Activation & Indole Metabolite Profiling in the Tryptophan Pathway

Our platform is highly versatile. For *in vitro* screens, we predominantly analyze bacterial culture supernatants to determine direct strain output. For *in vivo* and clinical studies, we have validated extraction protocols for complex matrices including fecal homogenates, serum/plasma, urine, and homogenized intestinal mucosal tissues. Our internal standards correct for the diverse matrix effects inherent in these different sample types.

Yes. Our reporter gene system can be run in multiple operational modes. To identify agonists (such as protective indole derivatives), we measure direct induction of luciferase activity. To evaluate potential antagonists, we co-incubate the sample with a known strong AhR agonist (like FICZ) and measure the dose-dependent suppression of the luminescent signal.

LC-MS provides the chemical identity and absolute concentration of the metabolites present, but it cannot definitively predict biological effect due to the complex interplay of synergistic or antagonistic compounds in a mixed biological sample. The reporter assay provides the functional proof of receptor activation. Utilizing both allows us to correlate the *presence* of a chemical with the *functional outcome*, meeting the highest standards for mechanism of action (MoA) validation.

While timelines vary based on sample volume and matrix complexity, a standard integrated project—comprising sample extraction, LC-MS/MS quantification, AhR reporter cell evaluation, and the final correlative bioinformatics report—typically requires 4 to 6 weeks from the receipt of samples.