FIG. 2.

Polarization and lumen formation of epithelial cell lines. (A) 40× phase-contrast microscopy images of MCF10A (top) and Caco2 (bottom) cell clusters at different time points. In the images of the microtissues at 100 h, the lumen edge is visible as a ring of higher contrast. (B) 40× confocal microscopy images of MCF10A (top) and Caco2 (bottom) microtissues fixed and stained for the localization of polarity markers (α₆ integrin for MC10A, actin for Caco2). The lumen edge is visible as an actin ring in the Caco2 image. Scale bars are 20 μm. Color images available online at www.liebertpub.com/tec