Basal lamina formation by epidermal cells in cell culture.

The formation of basal lamina in epidermal cell cultures was studied by electron microscopy. Epidermal cells were cultured on plastic dishes which were either uncoated or coated with collagen gel. The cells grew and stratified on the plastic substratum as well as on the collagen gel. While the cultures on the plastic surface showed no occurrence of hemidesmosomes and basal lamina at the interface with the plastic substratum, the cultures on the surface of the collagen gel showed development of hemidesmosomes leading to the focal occurrence of basal lamina at the interface of the collagen gel and the basal plasma membrane of basal cells. Thereafter, basal lamina occurred under the interhemidesmosomal areas in addition to the hemidesmosomal areas of the basal plasma membrane, forming a continuous layer by joining.