Figure 4.

Two-color click-PD screening generates base-modified aptamers with high affinity and specificity for Con A. (A) FACS plots of base-modified aptamer-displaying particles from the starting library and the aptamer pools from R1–3, where [Con A] = 1 nM and [PSA] = 250 nM. Percentages represent the subpopulation of particles in each quadrant. Quadrant IV (outlined in red) represents aptamers with high Con A and low PSA affinity, which were collected in each round. (B) High-throughput sequencing shows several highly enriched clusters of closely related sequences in the R3 pool. Each circle represents one enriched sequence, with colors indicating related clusters. The dotted line depicts our threshold for the most highly enriched sequences (>100-fold). Aptamer ConA-3-1 (red arrow) was selected for further characterization.