Collagen-fibronectin co-localization at the microtissue-substrate interface.

<p>Representative x-y projections of 2-day microtissues formed in response to either 25 nM or 100 nM fibronectin (FN). FN (green) and collagen (blue) were visualized as described in the legend to Figure 4. Z-slices (1-μm step size) were collected beginning below the collagen surface and extending above the microtissue. Images were reconstructed in 3D and then projected along the x-y plane. Arrows denote areas of co-localization (cyan). Note the non-overlapping FN and collagen signals on the apical and basal surfaces, respectively.