Force-extension curves and persistence length as a function of incubation time.

<p>(A) The force-extension curves of λ-DNA without drug (<i>L</i> = 16.5±0.04 µm, <i>P</i> = 44.0±2.1 nm), with 60 µM Pt(S,S-DACH) incubated for 3 h (<i>L</i> = 17.3±0.08 µm, <i>P</i> = 16.5±1.0 nm ) and 60 µM Pt(R,R-DACH) incubated for 3 h (<i>L</i> = 17.1±0.09 µm, <i>P</i> = 12.9±0.7 nm ). The data were fitted by the WLC model (Eq. 1). (B) The persistence lengths of λ-DNA treated with 60 µM Pt(R,R-DACH) or Pt(S,S-DACH) for different incubation times. Each data point was the mean of twenty independent measurements. The error bars corresponded to 95% confidence intervals. The difference was considered statistically significant when the <i>p</i> value of two-sample t-test was less than 0.05.