The Trans-Epithelial Permeability (TEP) Assay, is a cell-based assay used to evaluate the potential ocular irritancy of test chemicals by measuring the permeability of sodium fluorescein (or fluorescein leakage) through a confluent monolayer of Madin-Darby Canine Kidney (MDCK) cells.
The MDCK cell line is used since it forms tight junctions in a confluent monolayer similar to those formed in the outermost corneal and conjunctival epithelial layers. The disruption of the tight junctions by chemicals is one of the early events typical for most eye irritants, and thus measuring the permeation of fluorescein through the MDCK monolayer provides a mechanistically-relevant quantifiable endpoint.
IIVS utilizes a variety of TEP protocols to support raw materials screening, formulation development, and product safety assessment goals, while OECD Test Guideline 460 is used to identify ocular corrosives and severe irritants to satisfy regulatory classification and labeling requirements.
For more information, or to request a consultation with one of our study directors, contact IIVS Client Services.