As a next-generation assay, SENS-IS employs a Reconstructed human Epidermal (RhE) model and examines changes in the gene expression of 65 markers associated with epidermal response to pure compounds and formulations. The RhE model provides several features not represented in monolayer-based assays, including the barrier properties of the stratum corneum, metabolic activation/deactivation of substances and greater compatibility with insoluble compounds and formulations.
Using a well-vetted algorithm, the results from the qRT-PCR-based analysis are evaluated and a skin sensitization potency category is assigned. In addition, a skin irritation potential is provided as well. This approach permits greater ability to perform risk assessments on materials and products that are otherwise challenging with traditional models. The assay is currently being evaluated by a working group at OECD and a formal test guideline is expected to be published in the near future.
Assay Features
- Compatible with mixtures, formulations and pure substances
- Multiple-concentration protocol enables sensitization and irritation potency predictions
- Analysis of gene expression profiles that reflect multiple cellular events known to be important for contact sensitization, including inflammation, danger signals and cell migration
- Metabolically-competent tissues permit identification of pre- and pro-haptens
- Well-defined stratum corneum and 3-D nature of tissues provide accurate representation of human exposure
- High degree of reported sensitivity and specificity vs. LLNA and hRIPT
