To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Video 4 Movie S4. Time-lapse movie of a cell spreading on a homogeneous rigid polyacrylamide hydrogel, conjugated with gelatin in the same micropattern as for SU-8 islands on composite substrates. Images were captured every 10 min. Total duration, 13.2 h. Fibroblasts probe substrate rigidity with filopodia extensions before occupying an area Stephanie Wong, Wei-Hui Guo, and Yu-Li Wang PNAS. 2014. DOI: 10.1073/pnas.1412285111 Download Original Video Browse All Videos »