FIGURE 5.

Characterization of PRS model after iMc integration. Representative results from one experiment where all iMc strains were performed in parallel. Results were replicated within a total of three independent experiments. Histology quality control after HES staining: All samples displayed a correct 3D organization with fully differentiated epidermis and stratum corneum (pink), scale bar = 50 μm. Fontana Masson staining of skin sections reveals melanin as black dots quantified by the ratio of the surface covered by melanin over the epidermal surface and expressed by mean ± SD of the triplicate samples. Higher magnification shows melanocytes with dendrites and melanin pigment within epidermal keratinocytes, scale bar = 50 μm. TRP1 immunostaining on epidermal sheets highlights melanocytes (green cells) homogeneously distributed at the basal layer, scale bar = 100 μm. Pictures indicate the iMc counting values as mean ± SD cell/mm² calculated from each triplicate sample. DOPA reaction reveals more intense DOPA activity for cells of dark origin, scale bar = 50 μm. Immunostaining of tyrosinase on skin sections outlines in red the iMc localized at the basal layer of the epidermis, scale bar = 50 μm. Results were confirmed in other experiments (n = 3 for each strain).