Human In Vitro GI Toxicity Assay.
StemTox is a human GI toxicity assay that flags intestinal drug liabilities early, on RepliGut® Planar stem cell tissue. It reads barrier formation and renewal in one 96-well plate, in a five-day assay.
Start a StemTox studySee how it worksWhy GI toxicity slips through preclinical testing
Gastrointestinal toxicity is the most prevalent adverse event reported in clinical trials. It is often dose-limiting, which reduces drug efficacy and delays development.
The intestinal epithelium renews from rapidly dividing stem and progenitor cells. Many drugs that cause GI toxicity act on these same dividing cells. So a human GI toxicity assay that reads proliferation directly can catch these effects early. Animal studies miss human-specific responses, and regulators are shifting toward human-relevant New Approach Methodologies.
What the GI toxicity assay measures
StemTox reads three parameters in the same 96-well plate. Together they capture how a drug harms the cells that keep the gut barrier intact.
Barrier function with TEER
Trans-epithelial electrical resistance shows whether cells build and hold a functional barrier.
Proliferation with EdU
EdU incorporation counts actively dividing cells, the population most GI-toxic drugs hit.
Cell number with DAPI
DAPI quantification counts total cells, capturing loss of the epithelial population.
Together, EdU and DAPI describe renewal capacity. You can also add gene expression, protein expression, and immunohistochemistry from the same study.
Barrier formation and renewal in the same well
StemTox seeds human intestinal stem cells on RepliGut® Planar. As the cells proliferate and build an epithelial barrier, the assay reads these signals at once. It needs no complex fluidics and no long culture setup.
Barrier formation and renewal are measured simultaneously in each well. So you get a sensitive, selective picture of how a compound affects the cells that keep the gut intact.
From thawed cells to answers in five days
Thaw RepliGut® Planar stem cells and seed the 96-well plate.
Dose your compounds across the concentration range.
Cells proliferate and build the epithelial barrier.
Measure TEER for barrier formation.
Image EdU and DAPI for renewal, with results in five days.
StemTox predicts clinical GI toxicity
In a peer-reviewed study, StemTox was tested against 30 marketed drugs with known clinical diarrhea incidence, across three human donors. It predicted diarrhea risk with high balanced accuracy, and results varied little between donors. Read the published study.
Bortezomib and Colchicine both cause significant GI side effects in patients. StemTox detected their toxicity within two logs of the clinical Cmax. It also separated the mechanisms: Colchicine harmed only proliferating cells, while Bortezomib disrupted the epithelium in a non-specific way.
A broader endpoint range, in a faster timeline than organoids
Spherical organoids are variable and cannot support many key endpoints, including high-content imaging and barrier assays. Reaching a monolayer takes weeks and two culture expansions. RepliGut® Planar cultures cells directly on the membrane, so barrier formation and renewal read out in five days.
| Capability | 3D organoids | RepliGut® StemTox |
|---|---|---|
| Cytotoxicity | Yes | Yes |
| Gene and protein expression | Yes | Yes |
| Permeability | Limited | Yes |
| High-content imaging | Limited | Yes |
| Planar monolayer | Spherical form | Yes |
| Barrier integrity | Limited | Yes |
| Barrier formation | Limited | Yes |
| Barrier renewal capacity | Limited | Yes |
Check target expression in human gut tissue
Worried about on-target, off-tissue effects in the intestine?
Our team can query proprietary RepliGut® Planar Jejunum mRNA sequencing data. It spans days 2, 4, 6, and 8 in culture, plus metabolism gene inducers. We tell you whether your target is expressed in the gut, before you commit to a screen.
Ask our data teamExplore the platform and related services
StemTox is one of several ways to run RepliGut® in your program. Explore the full Services menu, our in vitro DMPK work, and the RepliGut® platform family.
RepliGut® Planar platform
See the human intestinal monolayer platform that powers StemTox, from stem cells direct to membrane.
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Explore InflammaScreenReady to screen for GI toxicity in human tissue?
Send us your compounds and get barrier formation and renewal data from our GI toxicity assay in a five-day study.
Start a StemTox study