Probing the Limits of Aptamer Affinity with a Microfluidic SELEX Platform
Figure 3
Screening of clones for target binding.
We quantified the relative binding affinities of 20 clones from each selection using a bead-based fluorescence binding assay at a single ssDNA concentration. NB indicates a non-binding control sequence included in each measurement. We chose the top binding sequences for further analysis and determination of equilibrium dissociation binding constant (Kd). (A) PDGF-BB with [ssDNA] = 0.50 nM, NB = Thrombin Clone #1. (B) Thrombin with [ssDNA] = 0.50 nM, NB = PDGF Clone #1. (C) ApoE with [ssDNA] = 35 nM, NB = Thrombin Clone #1.