title: A rapid field-use assay for mismatch number and location of hybridized DNAs.
abstract: Molecular dielectrophoresis (DEP) is employed to rapidly (<ms) trap ssDNA molecules in a flowing solution to a cusp-shaped nanocolloid assembly on a chip with a locally amplified AC electric field gradient. By tuning AC field frequency and DNA DEP mobility relative to its electrophoretic mobility due to electrostatic repulsion from like-charged nanocolloids, mismatch-specific binding of DNA molecules at the cusp is achieved by the converging flow, with a concentration factor about 6 orders of magnitude higher than the bulk, thus allowing fluorescent quantification of concentrated DNAs at the singularity in a generic buffer, at room temperature within a minute. Optimum flow rate and the corresponding hybridization rate change by nearly a factor of 2 with a single mismatch in the 26 base docking sequence and are also sensitive to the mismatch location. This dielectrophoresis and shear enhanced pico-molar sensitivity and SNP selectivity can hence be used for field-use DNA detection/identification.
authors.affiliation: Institute of Nanotechnology and Microsystems Engineering, Institute of Biomedical Engineering, Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan, Taiwan, ROC.
authors.forename: I-Fang
authors.initials: IF
authors.lastname: Cheng
authors.forename: Satyajyoti
authors.initials: S
authors.lastname: Senapati
authors.forename: Xinguang
authors.initials: X
authors.lastname: Cheng
authors.forename: Sagnik
authors.initials: S
authors.lastname: Basuray
authors.forename: Hsien-Chang
authors.initials: HC
authors.lastname: Chang
authors.forename: Hsueh-Chia
authors.initials: HC
authors.lastname: Chang
mesh_terms: D020137:Base Pair Mismatch; D004247:DNA / Q000737:chemistry*; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D013997:Time Factors
chemical_list: D004247:DNA