Improvements are made to a novel media that replace the requirement
for all protein growth factors by the addition to the medium of physiological concentrations
of retinyl acetate. The media are serum-free, companion cell or feeder layer-free
and organotypic, matrix free solutions for the cultivation of clonally competent
basal keratinocytes. The media and methods are useful in the production of epidermal
epithelial tissue that is suitable for skin grafting.