Fluorescence anisotropy analysis of equilibrium ssDNA binding by SSB
. ssDNA binding was measured using fluorescence anisotropy of Fl-(dT)20 oligonucleotide probe using the fluorescence of its 5′-fluorescein moiety using 480 nm excitation and 540 nm emission of fluorescein as described in Materials & Methods. Titration was carried out with SSBBA and fluorescence anisotropy of Fl-(dT)20 was measured. As indicated, anisotropy of free Fl-(dT)20 oligonucleotide probe was 44 ± 5 mA and that of the SSBBA·Fl-(dT)20 complex was 182 ± 6 mA. Anisotropy values were plotted against log of SSBBA concentration and the plots were analyzed by nonlinear regression using Prism 6.0. The error bars indicate standard deviation. [Inset] A simple plot of the data fitted to single association hyperbolic function.