Movie 4

Confocal reflectance images of the collagen matrix surrounding the MDA-MB-231 spheroid shown in M2. Locations of apparent lack of collagen I that develop over the time course of the movie are caused primarily by out of plane spheroid and invading cells limiting excitation light reaching the imaging plane. Images are taken are taken every 5 minutes starting at t≈7.75 h after collagen embedding of the spheroid. Length of movie is 6.25 hours. Movie is played back at 7 frames/s. Frames from this movie are shown in Fig. 2 in the main text. Scale bar = 25 μm.