Figure 3.

Distinctive mechanical stiffness in the diverse microenvironments is dependent on FAK signaling. Representative fluorescence images of phalloidin-stained F-actin, (red), vinculin for focal adhesion proteins (green) and HOECHST 33258 for cell nuclei (blue) of the U251 on the different durotactic substrates: bulk stiff (a,e,i,m), durotactic gradient flat (b,f,j,n), durotactic micropatterned substrate (Lines) (c,g,k,o) and bulk soft (d,h,l,p). The images are representative of one of three experiments conducted in duplicate. The images (m,n,o,p) are the merge of the (FITC, phalloidin-TRITC, and HOECHST 3325. Scale bars 100 µm.