Agarose Droplet Microfluidic Approach for Molecular Evolution of Aptamers

We have developed a novel method for efficient screening of affinity ligands (aptamers) from a complex single-stranded DNA (ssDNA) library by employing single molecule emulsion PCR based on agarose droplet microfluidic technology . Statistically diluted ssDNA of a pre-enriched library was encapsulated into individual uniform agarose droplets for highly efficient single molecule emulsion PCR to generate clonal agarose beads. The binding affinity of amplified ssDNA from each clonal agarose bead was tested via high-throughput flow cytometry. DNA clones with high binding affinity and low dissociation constant (Kd) were chosen as potential aptamers and can be directly used for downstream biomedical applications.