Fig. 5. Cells extended and retracted lamellipodia along the direction of the patterns. (A-D) Time-lapse microscopy of a cell cultured on grooves and ridges on a 400 nm pitch. The direction of the patterns can be clearly seen but, due to the resolution of these images, the observed pitch is not correct. (E-H) Cell on smooth silicon oxide. (A,E) 2.5 hours; (B,F) 9.5 hours; (C,G) 10.5 hours; (D,H) 12 hours after cell seeding.