title: Integrated microsystem for dielectrophoretic cell concentration and genetic detection.
abstract: We have directly integrated a continuous-flow, electrokinetic method of bacterial cell concentration with room temperature, sequence-specific genetic detection. The system we have developed traps cells from a continuous-flow sample stream via dielectrophoresis, providing a 160-fold increase in cell concentration. PDMS microvalves then define a 100 nL volume around the trapped cells to which cell lysis buffer and genetic detection components are introduced. Direct, optical detection of Escherichia coli MC1061 cells is then accomplished via the sequence-specific hybridization of an rRNA-directed optical molecular beacon. This integrated microsystem is capable of sequence-specific genetic detection of 25 cells within 30 min.
authors.affiliation: California Nanosystems Institute and Department of Mechanical and Environmental Engineering, University of California-Santa Barbara, Santa Barbara, CA 93106, USA.
authors.forename: Eric T
authors.initials: ET
authors.lastname: Lagally
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Lee
authors.forename: H T
authors.initials: HT
authors.lastname: Soh
mesh_terms: D004247:DNA / Q000737:chemistry; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D046209:Electrophoresis, Microchip / Q000379:methods*; D004926:Escherichia coli / Q000378:metabolism; D007700:Kinetics; D008856:Microscopy, Fluorescence; D015233:Models, Statistical; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000379:methods*; D015345:Oligonucleotide Probes; D009841:Oligonucleotides / Q000737:chemistry; D012329:RNA, Bacterial / Q000032:analysis; D012335:RNA, Ribosomal / Q000737:chemistry; D012336:RNA, Ribosomal, 16S / Q000737:chemistry; D012828:Silicones / Q000737:chemistry; D013997:Time Factors
chemical_list: D004129:Dimethylpolysiloxanes; D015345:Oligonucleotide Probes; D009841:Oligonucleotides; D012329:RNA, Bacterial; D012335:RNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012828:Silicones; C013830:baysilon; D004247:DNA