title: An Integrated Microfluidic SELEX Approach Using Combined Electrokinetic and Hydrodynamic Manipulation.
abstract: This article presents a microfluidic approach for the integration of the process of aptamer selection via systematic evolution of ligands by exponential enrichment (SELEX). The approach employs bead-based biochemical reactions in which affinity-selected target-binding oligonucleotides are electrokinetically transferred for amplification, while the amplification product is transferred back for affinity selection via pressure-driven fluid flow. The hybrid approach simplifies the device design and operation procedures by reduced pressure-driven flow control requirements and avoids the potentially deleterious exposure of targets to electric fields prior to and during affinity selection. In addition, bead-based reactions are used to achieve the on-chip coupling of affinity selection and amplification of target-binding oligonucleotides, thereby realizing on-chip loop closure and integration of the entire SELEX process without requiring offline procedures. The microfluidic approach is thus capable of closed-loop, multiround aptamer enrichment as demonstrated by selection of DNA aptamers against the protein immunoglobulin E with high affinity ( KD= 12 nM) in a rapid manner (4 rounds in approximately 10 h).
authors.affiliation: 1 Department of Mechanical Engineering, Columbia University, New York, NY, USA.
authors.forename: Timothy
authors.initials: T
authors.lastname: Olsen
authors.affiliation: 1 Department of Mechanical Engineering, Columbia University, New York, NY, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhu
authors.affiliation: 1 Department of Mechanical Engineering, Columbia University, New York, NY, USA.
authors.forename: Jinho
authors.initials: J
authors.lastname: Kim
authors.affiliation: 2 Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, China.
authors.forename: Renjun
authors.initials: R
authors.lastname: Pei
authors.affiliation: 3 Department of Medicine, Columbia University, New York, NY, USA.
authors.forename: Milan N
authors.initials: MN
authors.lastname: Stojanovic
authors.affiliation: 1 Department of Mechanical Engineering, Columbia University, New York, NY, USA.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Lin
mesh_terms: D004586:Electrophoresis / Q000295:instrumentation / Q000379:methods*; D057446:Hydrodynamics; D056656:Lab-On-A-Chip Devices; D044085:Microfluidics / Q000295:instrumentation / Q000379:methods*; D021141:Nucleic Acid Amplification Techniques / Q000295:instrumentation / Q000379:methods; D052156:SELEX Aptamer Technique / Q000295:instrumentation / Q000379:methods*
keywords: lab-on-a-chip; microfluidics; molecular biology; systems