Ultrastructural studies on the external surface coat of epidermal cells: alcian blue-lanthanum nitrate staining...

The external surface coat on mouse epidermal cells has been studied during epidermal wound healing in suction-induced intact subepidermal blisters. By sequentially incorporating the cationic dye Alcian blue and the electron opaque tracer lanthanum nitrate into the primary and secondary fixatives for electron microscopy (AB/LN staining), we have demonstrated a selective staining of the epidermal surface coat. At 12 and 24 h after wounding, AB/LN staining always occurred on opposing cell membranes of adjacent epidermal cells. No staining was seen along epidermal cell plasmalemmas exposed to the blister cavity or opposite the basal lamina. The full significance of this differential AB/LN staining during wound healing is not presently known. It is suggested that the presumed anionic sites that are binding the AB/LN stain may play a role in maintaining integrity during wound healing.