Fig. 2. Characterization of long-term cultures of esophageal cells grown on filters. (A-C) Confocal analysis of immunocytochemistry labeling. (A) CK14 was strongly expressed in the basal cell layer, whereas (B) CK4 was expressed in suprabasal cells. (C) xz confocal section after labeling of nuclei (red) and CK4 (green) showing the cell stratification and the suprabasal epithelioid distribution of CK4 positive cells. Scale bar, 20 µm. (D) Transmission electron microcopy view of pluristratified mouse esophageal epithelioid cells grown on filter. Insert: enlarged view of a desmosome (f: filter). Scale bar, 2 µm.