Differences in the urea-extracted proteins of mouse epidermis and squamous cell carcinomata determined by fluorescence microscopy.

Fluorescence microscopy was used to demonstrate differences in the urea-extractable antigens of mouse epidermis and squamous cell carcinoma. When serum- and normal tissue sediment-absorbed antisera prepared against mouse epidermal urea-extracted proteins were further absorbed with carcinoma urea antigens, antisera specific for epidermis resulted. When antisera raised against the urea-extractable proteins of mouse squamous cell carcinomata were serum- and normal tissue sediment-absorbed and then further absorbed with epidermal urea antigens, antisera were prepared which stained papilloma and carcinoma, but not epidermis, and thus these antisera were not specific for carcinoma. Antisera prepared against the urea-extractable proteins of human epidermis reacted in immunodiffusion in agar with the epidermal urea proteins, but not with human squamous cell carcinoma urea proteins. Also antisera prepared against the carcinoma urea-extractable proteins reacted with these proteins in agar, but no reaction occurred with the epidermal urea-extractable proteins.