The Separation and Cultivation of Basal and Differentiating Cells from Hairless Mouse Epidermis

An earlier described method for the separation of basal and differentiating cells from hairless mouse epidermis (1) has been further studied. 1) A more precise quantitative determination of the specificity of the separation procedure has been performed by radioactive labeling of DNA in basal cells. By autoradiography the number of labeled basal cells in each fraction was counted and the purity calculated. The purity of the basal cell suspensions was 87.0 per cent and the differentiating cells 77.8 per cent. As purely morphological judgement is insufficient to distinguish an early differentiating cell from a basal cell, such specificity tests are necessary to ensure a correct separation technique. 2) The viability of the separated cells has been studied by culture in diffusion chambers up to 10 days. The cells appeared intact the first 24 hours, and thereafter a pronounced cell loss took place. The surviving differentiating cells appeared to continue their keratinization ending after 7 days, as expected from their turnover time in vivo. Basal cells either went into differentiation or proliferation, but the latter process was outweighed by the cell loss