Figure 2.

(A) Schematic of attachment linking beads to DNA. For some of the single-molecule nuclear uptake experiments, streptavidin was added to the free biotin moieties, and then to biotinylated NLS peptide. (B and C) The free biotin was used to bridge the bead-DNA construct to the microscope slide, which was precoated with biotinylated-BSA. (B) Test for DNA condensation or lysis in egg extract. The plot shows the relative extended length of DNA molecules vs. time in extract. Lines of a given color represent first and last stretches, whereas the horizontal axis shows the time since exchange of buffer by cytosol. (C) Recoil kinetics of beads stretched from an anchor point on the glass surface in buffer and in extract (red points, in PBS buffer; blue points, in extract).