A stain combining periodic acid with the fluorochrome acriflavine (the fluorescent periodic acid-acriflavine [FPAA] reaction) was applied to specimens of normal adult human skin for study of the subepidermal basement membrane (BM). Advantages over conventional PAS technique were enhanced delineation of structural details and color contrast. In specimens from all body regions studied the BM showed variations in thickness, reticulation or stratification, and defects ranging from fragmentation to absence. These variations were least pronounced in plantar skin. Correlations of BM changes with basal layer morphology were noted.
Winter V, Levan NE. Basement Membrane of Normal SkinA Study Using the Fluorescent Periodic Acid—Acriflavine Method. Arch Dermatol. 1970;102(4):418-421. doi:10.1001/archderm.1970.04000100066013