Analysis of Triton X-100 insoluble proteins of human chorionic and amniotic tissues with special emphasis on intermediate filaments.

The intermediate filament composition of the chorionic villi of the human full-term placenta and that of the amniotic sac was analysed. The analysis of the protein pattern of the Triton X-100 resistant tissue residues on SDS-polyacrylamide gel did not help us in intermediate filament identification because of the protein heterogeneity of the samples. The in vitro polymerization-depolymerization of the detergent resistant tissue proteins did not result in considerable enrichment of the intermediate filament proteins either. The direct immunological identification done by immunoblotting electrophoresis on the detergent resistant tissue residues, revealed that vimentin and cytokeratins were synthetized in detectable quantities in the human extraembryonal tissues.