title: Planar chip device for PCR and hybridization with surface acoustic wave pump.
abstract: We have developed a microfluidic device operating at a planar surface instead of a closed channel network. The fluid is transported in single droplets using surface acoustic waves (SAW) on a piezoelectric LiNbO(3) substrate. The surface of the piezo is chemically structured to induce high contact angles of the droplets or enclose areas where the liquid can wet the substrate. Combining the SAW technique with thin film resistance heaters, a biological analysis chip with integrated DNA amplification by PCR and hybridization was designed. To prevent evaporation of the PCR reagents at high temperatures the sample is enclosed in droplets of mineral oil. On this chip the SAW resolves dried primers, shifts the oil capped liquid between the two heaters and mixes during hybridization. The chip is able to perform a highly sensitive, fast and specific PCR with a volume as low as 200 nl. During the temperature cycles an online monitoring of the DNA concentration is feasible with an optical unit, providing a sensitivity of 0.1 ng. After PCR the product is moved to the second heater for the hybridization on a spotted DNA array. With our chip we were able to detect a single nucleotide polymorphism (SNP) responsible for the Leiden Factor V syndrome from human blood.
authors.affiliation: Advalytix AG, Eugen-Sanger-Ring 4, 85649 Brunnthal, Germany. guttenberg@advalytix.de
authors.forename: Zeno
authors.initials: Z
authors.lastname: Guttenberg
authors.forename: Helena
authors.initials: H
authors.lastname: Muller
authors.forename: Heiko
authors.initials: H
authors.lastname: Habermüller
authors.forename: Andreas
authors.initials: A
authors.lastname: Geisbauer
authors.forename: Jürgen
authors.initials: J
authors.lastname: Pipper
authors.forename: Jana
authors.initials: J
authors.lastname: Felbel
authors.forename: Mark
authors.initials: M
authors.lastname: Kielpinski
authors.forename: Jürgen
authors.initials: J
authors.lastname: Scriba
authors.forename: Achim
authors.initials: A
authors.lastname: Wixforth
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D004247:DNA / Q000737:chemistry*; D004867:Equipment Design; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods; D009038:Motion; D009556:Niobium / Q000737:chemistry; D009693:Nucleic Acid Hybridization / Q000379:methods; D010087:Oxides / Q000737:chemistry; D010316:Particle Size; D016133:Polymerase Chain Reaction / Q000295:instrumentation* / Q000379:methods; D012680:Sensitivity and Specificity; D013499:Surface Properties
chemical_list: D010087:Oxides; D009556:Niobium; C091692:lithium niobate; D004247:DNA