dsDNA fit to wlc model Hooke's law 0.4 Extension(/L) After Bustamante et al., Current Opinion in Structural Biology, 2001FJC Hooke’s law dsDNA fit to WLC model 100 10 1 0.1 0.01 0 0.2 0.4 0.6 0.8 1.0 1.2 Force (pN) Extension (x/L) After Bustamante et al., Current Opinion in Structural Biology, 2001