Demonstration and partial characterization of a novel soluble antigen present in keratocysts.

Keratocyst antigen was demonstrated in the fluid of keratinizing odontogenic cysts (primordial cysts) but not in fluids of other cyst types. The antigen was not present in plasma or saliva. It resisted collagenase digestion and did not react with keratin antibodies. In gel filtration, the antigen migrated as a single peak and gave a molecular weight of about 50 000 when analyzed in SDS-polyacrylamide gel electrophoresis. In immunoelectrophoresis, it migrated in the prealbumin region and was localized in epithelial cells of the cyst capsule, when studied by a double-antibody fluorescence technique. The origin and function of the keratocyst antigen is unclear but it may be a soluble marker for keratocyst differentiation.