Figure 2.

Measurements of lamellipodial activity and cell motility on substrates of various flexibilities. (A, B) Fluctuation of the lamellipodia of NRK cells cultured on substrates of varying flexibilities. Numbers in A indicate the percentage concentration of bis-acrylamide. Images of cells were recorded every 2 min over a period of 10 min and active lamellipoda were traced and overlaid to generate the plots. The degree of lamellipodial protrusion/retraction was then quantified based on the SD of the position of seven randomly chosen points along the active edge. Fifteen cells were analyzed under each bis-acrylamide concentration (B). Lamellipodia become less active with increasing rigidity of the substrate. (C) Rate of locomotion of 3T3 cells on substrates of varying flexibilities. Cells become less motile with increasing rigidity of the substrate.