The EpiSkin models are obtained by culturing adult human keratinocytes on a collagen substrate in conditions which permit their terminal differentiation and the reconstruction of an epidermis with a functional horny layer.

The human keratinocytes come from mammary samples obtained from healthy consenting donors during plastic surgery. HIV 1 & 2, B and C hepatitis tests are carried out on the donor bloods as well as verification of the bacteriological & fungal sterility of the cells and absence of mycoplasma.

EpiSkin is produced in accordance with the quality reference norm ISO 9001, ensuring traceability and reproducibility of the epidermal tissues.

The reproducibility of each batch is checked by histological analysis taking into account the general organisation, the stratification of the epidermis, the nucleation of the basal layer, the size of the intercellular spaces, adhesion of the basal

layer to the support, the quantity of granular cells and the thickness of the horny layer. Each criterion is scored from 0 to 4. The maximum score is 28. The minimum score for histology acceptability of the model is 19/28.

The reproducibility of the response of each EpiSkin batch is tested against a reference irritant: SDS. The IC50 of the surfactant is measured by the MTT assay after 18 hours of contact. The minimum score for acceptability of the model is icso ≥ 1mg/ml.