Figure 2.

(a) Predictions from simulations and (b) observations from Engler et al. [6] of hMSCs seeded on elastic substrates uniformly coated with collagen. In the experimental immunofluorescence images, the focal adhesions are coloured green, actin red and nucleus blue and purple, and a similar scheme is followed in the predictions, with the focal adhesions parametrized by the magnitude of the normalized traction $\hat{T}$ (see electronic supplementary material, s1.5.1 for details of the method used to construct immunofluorescence-like images from the simulated results). Scale bar, 20 µm. (c) Predictions of stress-fibre intensity as a function of substrate stiffness compared with observations from Zemel et al. [36] for hMSCs seeded on glass substrates. In the simulations, we use total stress-fibre concentration ${\hat{N}}_{\mathrm{b}}\equiv 1-{\hat{N}}_{\mathrm{u}}$ to parametrize the stress-fibre intensity. (Online version in colour.)