Localization of specific carbohydrate configurations in human skin using fluorescein-labelled lectins

The binding of three fluorescein-labelled lectins by normal human skin has been studied. The patterns of bound fluorescence seen were characteristic for each lectin, indicating that saccharide residues were available for lectin localization in the skin. Concanavalin A (glucose and mannose specific) and ricin 120 (galactose specific) presented similar patterns of localization of fluorescence in the epidermis and dermis. Both lectins presented a continuous band at the dermo--epidermal junction, but with concanavalin A the band was broader, while with ricin 120 the junctional band was thinner and more closely associated with the epidermal interface. With the peanut lectin (galactose specific) fluorescence outlined the periphery of the keratinocytes in the upper Malpighian and granular cell layers only; no junctional band was seen and the dermal appendages and collagen did not fluoresce. The stratum corneum did not fluoresce with any of the lectins studied.