Fig. 6. Colocalization of trichoplein with K8/18 and desmoplakin in polarized Caco-2 cells. Caco-2 cells were cultured on laminin-coated cell culture inserts for more than 3 days. They were fixed and immunostained with antibodies as indicated and analyzed by laser-scanning confocal microscopy. Images a-f and j-o are in the X-Y plane. Images g-i are in the Z-section. (A) Caco-2 cells showed concentrations of K8/18 in the cortical cytoskeleton with higher density in apical region (a,d,g). At the upper and the middle level (a-i), trichoplein associates with K8/18 in a speckled pattern. Trichoplein also concentrated at the cell-cell border of the upper level (b). (B) Trichoplein colocalized with desmoplakin clearly at the cell-cell border of the upper level (j-l) and partially at the middle level (m-o). Bar, 10 µm.