Synthesis of basal lamina by epidermal cells in vitro

In epidermal cell cultures grown on type I collagen, the in vitro synthesis of basal lamina was studied by electron microscopy and indirect immunofluorescence with anti-type IV collagen antibody. The newly-formed basal lamina and type IV collagen were observed in a linear pattern beneath the epidermal cells. The observations strongly suggest that the basal lamina containing type IV collagen is newly synthesized by the epidermal cells.