FIGURE 11.

Force-extension curves predicted by the FWLC solution for L = 500 nm (L/p = 10) with one bead. We implemented half-constrained boundary conditions at both ends of the chain but included bead rotational fluctuations. The predicted molecular extensions, x (after the bead radius has been subtracted), agree with the no-bead prediction for large force, but decrease more rapidly as the force decreases. Such a reduction in x becomes more significant for bigger sized beads. The curves for two different beads (R = 100 and 250 nm) are indistinguishable over the theoretically valid force range (80 fN < F < 8 pN). Below 80 fN (shaded), the predicted x for a bead with R = 250 nm bead decreases faster than x for a bead with R = 100 nm.