title: Improving aptamer selection efficiency through volume dilution, magnetic concentration, and continuous washing in microfluidic channels.
abstract: The generation of nucleic acid aptamers with high affinity typically entails a time-consuming, iterative process of binding, separation, and amplification. It would therefore be beneficial to develop an efficient selection strategy that can generate these high-quality aptamers rapidly, economically, and reproducibly. Toward this goal, we have developed a method that efficiently generates DNA aptamers with slow off-rates. This methodology, called VDC-MSELEX, pairs the volume dilution challenge process with microfluidic separation for magnetic bead-assisted aptamer selection. This method offers improved aptamer selection efficiencies through the application of highly stringent selection conditions: it retrieves a small number (<10(6)) of magnetic beads suspended in a large volume (>50 mL) and concentrates them into a microfluidic chamber (8 μL) with minimal loss for continuous washing. We performed three rounds of the VDC-MSELEX using streptavidin (SA) as the target and obtained new DNA aptamer sequences with low nanomolar affinity that specifically bind to the SA proteins.
authors.affiliation: Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, USA.
authors.forename: Seung Soo
authors.initials: SS
authors.lastname: Oh
authors.forename: Kareem M
authors.initials: KM
authors.lastname: Ahmad
authors.forename: Minseon
authors.initials: M
authors.lastname: Cho
authors.forename: Seon
authors.initials: S
authors.lastname: Kim
authors.forename: Yi
authors.initials: Y
authors.lastname: Xiao
authors.forename: H Tom
authors.initials: HT
authors.lastname: Soh
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D008280:Magnetics; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D052156:SELEX Aptamer Technique; D019809:Streptavidin / Q000032:analysis
chemical_list: D052157:Aptamers, Nucleotide; D019809:Streptavidin