FIG. 1.

Mechanical properties of human pluripotent stem cells (hPSCs). (A–H) Actin stress fibers near the apical (A–D) and basal (E–H) surfaces of human embryonic stem cells (hESCs) at an undifferentiated state or at day 2, 5, and 10 postdifferentiation. Scale bar: 20 μm. (I) Comparison of elasticity among hESCs, hiPSCs, and more differentiated cells. ^#p<0.05 relative to adipose derived stem cells. *p<0.05 relative to IMR90 fibroblasts. (J) Compliance of stem cell nuclei compared to other cell types. (K) Nuclear deformations of hESCs through microaspiration, control (top), and cation-treated (bottom). Arrows indicate the extent of aspiration into a micropipette (dashed lines). Scale bar: 3 μm. Adapted with permission from Khatau et al.,²² Hammerick et al.,¹⁹ and Discher and coworkers.²⁴ Color images available online at www.liebertpub.com/teb