Fig. 1. Schematics show the CHO cells positioned (a) on top of, (e) within, or (i) on the substrate beneath the collagen hydrogel (green). The region outlined with a red-dashed line approximates the location where fluorescence imaging was performed. Volumetric confocal microscopy images of CHO cells that were labeled with Hoechst nuclear stain (blue) (b and c) on top of, (f and g) within, or (j and k) beneath a collagen hydrogel, which was labeled with CFSE (green). White arrows indicate the positions of the cells. Cross-sectional confocal microscopy images acquired of the sample containing cells (white arrows) positioned (d) on top of, (h) within, or (l) beneath the collagen hydrogel. The z-coordinate where the image was taken is shown on the figure. Low values are closer to the substrate beneath the hydrogel and high values are closer to the top surface of the hydrogel.
