Reconstructed Human Epidermis Model Test

Method Description

The EpiSkin™ model is a three dimensional reconstructed human epidermis that, once established, comprises of a main basal, supra basal, spinous and granular layers and a functional stratum corneum (the outer barrier layer of skin). The use of the model specifically for skin irritation testing involves the topical application of a test chemical followed by an assessment of cell viability, and specifically cytotoxicity (as measured via the MTT assay). Reductions in cell viability are then expressed as a % of the negative control. The % reduction is then used to predict the irritation potential of a chemical. A substance is considered to be irritating to skin (i.e. categorised as R38) if tissue viability after exposure and post incubation (see protocol, below) is less than or equal to 50%. Cell viability above 50% is considered a marker of a chemical being a non-irritant.