Figure 10.

Fluctuations of DNA extension averaged over time interval Δt. The amplitudes of the extension fluctuations, σ_x (Δt), were obtained in the BD simulation for the model chain with attached bead of 1 μm in diameter (▾) and without any bead (▴). The stretching force was equal to 0.1 pN. For a sufficiently large value of Δt, the average values of extension for adjacent time intervals are not correlated, so the value of σ_x (Δt) has to be proportional to $1/\sqrt{\Delta t}$ (this dependence is shown by the dotted line). The simulated dependences satisfy this condition for Δt > 10 ms and Δt > 100 ms for the chains without and with the bead, respectively. This consideration allows extrapolation of the simulated results to larger values of Δt that are not accessible in the simulation directly.