The ultrastructural localization of keratin proteins and carcinoembryonic antigen in malignant mesotheliomas.

The immunoultrastructural localization of keratin proteins and carcinoembryonic antigen (CEA) in mesothelioma cells was accomplished with a low-temperature embedding colloidal gold technique. The keratin antiserum labeled only intermediate filaments. These filaments surrounded the cytoplasmic organelles and were inserted into desmosomes. The CEA antiserum labeled cytoplasmic vesicles and droplets. No definite labeling of microvilli was observed.