Scanning laser confocal microscopy of TECs in monolayer cultures. (A) Depicts a relatively low power view of staining with the directly FITC-labeled pan-cytokeratin antibody (PKC-26) showing that the majority of TEC cells in the monolayers are cytokeratin positive. (B) Represents the same field stained with propidium iodide to reveal the cell nuclei and (C) is the merged image showing that essentially all the cells are cytokeratin positive (bar = 11.3 μm). (D) Is a higher power image of TECs showing the characteristic filamentous structure of cytokeratin expressed by epithelial cells (bar = 7.2 μm).