Figure 5.
One-basepair positional stability. (A) DNA contour length (L) measurement with (green) and without (red) active stabilization of both the trap and surface. Data taken at F = 6 pN and xbd = 70 nm, and filtered using a Savitzky-Golay window (light = 5 Hz, dark = 0.2 Hz). (B) The integrated noise for traces in panel A. With active stabilization (green), the positional stability of the system increases fourfold at 0.1 Hz and is 1 bp (0.34 nm) over Δf = 0.03–2 Hz. (C) Record of L versus time over 5 min, with the same conditions and trace color as in panel A. (D) The integrated noise in L (Δf = 0.1–10 Hz) as a function of force at two different lengths (556 nm (black triangles), 1007 nm (blue circles)). (E) Record of length versus time during a 3.4-pN increase in force (purple). Trace color and conditions same as in panel A. Traces offset vertically for clarity in panels A, C, and E.