title: Continuous Separation of DNA Molecules by Size Using Insulator-Based Dielectrophoresis.
abstract: Separation of nucleic acids has long served as a central goal of analytical research. Innovations in this field may soon enable the development of rapid, on-site sequencing devices that significantly improve both the availability and accuracy of detailed bioinformatics. However, achieving efficient continuous-flow operation and size-based fractionation of DNA still presents considerable challenges. Current methods have not yet satisfied the need for rapid fractionation of size-heterogeneous nucleic acid samples into specific and narrow size distributions. Dielectrophoretic (DEP) mechanisms integrated in microfluidic devices offer unique advantages for such applications, including short processing times, microscale reaction volumes, and the potential for low cost and portability. To facilitate such developments, we have adapted a microfluidic constriction sorter device to separate a wide range of nucleic acid analytes into distinct microchannel outlets. This work demonstrates selective and tunable deflection of DNA using alternating current (AC) insulator-based dielectrophoresis. We report conditions for size-based DEP sorting of 1.0, 10.2, 19.5, and 48.5 kbp dsDNA analytes, including both plasmid and genomic DNA. Applied potentials range from 200 to 2400 Vppwith frequencies ranging from 50 Hz to 20 kHz. These conditions result in sorting efficiencies up to 92% with a strong dependence on applied potentials and frequencies. In low-frequency AC fields, long DNA molecules form macro-ion clusters. This behavior is associated with an apparent shift from positive to negative DEP sorting behavior. Using a finite element model, we characterize the dynamics of sorting in the microdevice and link differential sorting to differences in dielectrophoretic mobility. We propose the use of a continuous-flow sorting strategy to facilitate future coupling to next generation sequencing approaches.
authors.affiliation: School of Molecular Sciences, Arizona State University , P.O. Box 871604, Tempe, Arizona 85287, United States.|Center for Applied Structural Discovery, The Biodesign Institute , Tempe, Arizona 85281, United States.
authors.forename: Paul V
authors.identifier: 0000-0002-1676-326X
authors.initials: PV
authors.lastname: Jones
authors.affiliation: School of Molecular Sciences, Arizona State University , P.O. Box 871604, Tempe, Arizona 85287, United States.|Center for Applied Structural Discovery, The Biodesign Institute , Tempe, Arizona 85281, United States.
authors.forename: Gabriel L
authors.initials: GL
authors.lastname: Salmon
authors.affiliation: School of Molecular Sciences, Arizona State University , P.O. Box 871604, Tempe, Arizona 85287, United States.|Center for Applied Structural Discovery, The Biodesign Institute , Tempe, Arizona 85281, United States.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Ros
mesh_terms: D010582:Bacteriophage lambda / Q000235:genetics; D004247:DNA / Q000302:isolation & purification*; D004279:DNA, Viral / Q000302:isolation & purification; D004586:Electrophoresis / Q000295:instrumentation / Q000379:methods*; D056656:Lab-On-A-Chip Devices; D010957:Plasmids / Q000235:genetics
chemical_list: D004279:DNA, Viral; D004247:DNA