SUBSTRATE AND NUTRIENT EFFECTS UPON EPIDERMAL BASAL CELL ORIENTATION AND PROLIFERATION

Abstract

Basal cells of embryonic epidermis remain oriented and mitotically active if cultured in vitro on a suitable substrate and in the presence of chicken embryo juice or a macromolecular fraction therefrom. Millipore filters, tropocollagen gels, or frozen-thawed dermls are effective substrates, whereas lens paper or 100,000-g centrifugal pellets are not. The active fraction from embryo juice is non-dlalyzable, heat-labile, trypsin-sensitive, and sediments between 2000 and 100,000 g.