Figure 2.

(A) Number of steps versus adhesion rate reveals that PC3 cells after antibody treatment interact nonspecifically, like on BSA. For each probed interaction, 10 different cells with at least 100 force traces each were measured. Standard errors are given as error bars. (B) Histogram of the step positions and (C) corresponding slopes of untreated PC3 cells on collagen substrate. (Gray subsection) Membrane tethers (Gaussian fitted on top). (D) A smoothed two-dimensional probability density plot of the slope versus step position reveals cumulated jumps and a few longer tethers. (Black lines) Zero slope and 1 μm step position. (White line at −10 pN/μm) Apparent best border between tether region and jump region. (Inset, colored bar codes for the probability densities.) To see this figure in color, go online.