title: Denaturing gradient-based two-dimensional gene mutation scanning in a polymer microfluidic network.
abstract: An integrated two-dimensional (2-D) DNA separation platform, combining standard gel electrophoresis with temperature gradient gel electrophoresis (TGGE) on a polymer microfluidic chip, is reported. Rather than sequentially sampling DNA fragments eluted from standard gel electrophoresis, size-resolved fragments are simultaneously electrokinetically transferred into an array of orthogonal microchannels and screened for the presence of sequence heterogeneity by TGGE in a parallel and high throughput format. A bulk heater assembly is designed and employed to externally generate a temporal temperature gradient along an array of TGGE channels. Extensive finite element modeling is performed to determine the optimal geometries of the microfluidic network for minimizing analyte band dispersion caused by interconnected channels in the network. A pH-mediated on-chip analyte stacking strategy is employed prior to the parallel TGGE separations to further reduce additional band broadening acquired during the electrokinetic transfer of DNA fragments between the first and second separation dimensions. A comprehensive 2-D DNA separation is completed in less than 5 min for positive detection of single-nucleotide polymorphisms in multiplex PCR products that vary in size and sequence.
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA.
authors.forename: Jesse S
authors.initials: JS
authors.lastname: Buch
authors.forename: Frederick
authors.initials: F
authors.lastname: Rosenberger
authors.forename: W Edward
authors.initials: WE
authors.lastname: Highsmith
authors.forename: Christopher
authors.initials: C
authors.lastname: Kimball
authors.forename: Don L
authors.initials: DL
authors.lastname: DeVoe
authors.forename: Cheng S
authors.initials: CS
authors.lastname: Lee
mesh_terms: D004247:DNA / Q000737:chemistry; D004252:DNA Mutational Analysis / Q000295:instrumentation / Q000379:methods*; D015180:Electrophoresis, Gel, Two-Dimensional / Q000295:instrumentation / Q000379:methods*; D020342:Finite Element Analysis; D005820:Genetic Testing; D006863:Hydrogen-Ion Concentration; D044085:Microfluidics / Q000295:instrumentation / Q000379:methods*; D008962:Models, Theoretical; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011108:Polymers / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013696:Temperature; D013997:Time Factors
chemical_list: D011108:Polymers; D004247:DNA