Figure 3.

Hybridization kinetic curves at different target concentration and probe surface density. (a) RPI binding curves measured on the same sensor on spots with probe density 0.19 ng/mm² (green), 0.24 ng/mm² (purple), 0.38 ng/mm² (red), and 0.41 ng/mm² (cyan), for increasing concentrations of target strand in solution: (from left to right) 0.5, 2.5, 12.5, 62.5, 312.5, and 1562.5 nM. The black curves are fits to the data by single exponential growth functions. (b) Equilibrium asymptotic amplitudes and (c) kinetic rates obtained from exponential fits of the hybridization curves of panel a (blue squares). The blue lines are fits with amplitudes and rates obtained from a Langmuir model. The last two points at the largest concentrations are excluded from the fit of the rates. The green lines (b) and the green triangles (c) are the values obtained from the fit with the NLER model. The red lines represent the Langmuir behavior extrapolated from the NLER fit for Γ = 0. Average R²-values for the equilibrium curves fits with Langmuir and NLER models reported in (b) are 0.987 ± 0.003 and 0.998 ± 0.001, respectively. The residual analysis is reported as Supporting Materials and Methods. To see this figure in color, go online.