Figure 1. Three-dimensional Caco-2 spheroids express the TJ, the AJ proteins and the peri-junctional actin ring.

[A] Protein expression of ZO-1 and occludin was detected using immunofluorescence microscopy (original magnification, ×63) with mouse anti- ZO-1 (green), rabbit anti-occludin (red) followed by DAPI nuclear stain (blue). [B] Protein expression of E-cadherin and ß-catenin was detected using immunofluorescence microscopy (original magnification, ×63) with mouse anti-E-cadherin (green), rabbit anti-ß-catenin (red); and nuclei were counterstained with DAPI. [C] Actin filaments were detected using fluorescence microscopy (original magnification, ×63) with phalloidin (red) and nuclei were counterstained with DAPI (blue). Representative images captured from cross-section of the spheroids are shown. The bars indicate 10 µm.