title: An RNA-DNA hybridization assay chip with electrokinetically controlled oil droplet valves for sequential microfluidic operations.
abstract: A novel RNA-DNA hybridization microfluidic chip for detecting pathogens was developed. The on-chip sequential operations of reagent delivery and washing processes in the hybridization assay were performed by gravity-based pressure-driven flow controlled by a pair of electrokinetically controlled oil-droplet sequence valves (ECODSVs). Numerical method was used to simulate the fluidic processes of reagents in the complex microchannel network. Based on the parameters determined from the numerical simulations, a reasonable hybridization assay microfluidic chip was developed. The application of this on-chip assay to detect Salmonella was demonstrated. Significantly shortened assay time (25 min) and a 3-20-fold reduction in reagent/sample consumption were achieved. The detection limit was 10³ CFU/mL which is comparable to the conventional assay. With further development of automatic control and the improvement of the detection strategy, this microfluidic RNA-DNA hybridization assay technique has a potential for point-of-testing applications.
authors.affiliation: Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada.
authors.forename: Xuan
authors.initials: X
authors.lastname: Weng
authors.forename: Hai
authors.initials: H
authors.lastname: Jiang
authors.forename: Chan Hee
authors.initials: CH
authors.lastname: Chon
authors.forename: Shu
authors.initials: S
authors.lastname: Chen
authors.forename: Honghe
authors.initials: H
authors.lastname: Cao
authors.forename: Dongqing
authors.initials: D
authors.lastname: Li
mesh_terms: D003198:Computer Simulation; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D055664:Electrochemical Techniques; D004867:Equipment Design; D056656:Lab-On-A-Chip Devices; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D008954:Models, Biological; D009693:Nucleic Acid Hybridization / Q000379:methods*; D009821:Oils; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*; D012313:RNA / Q000737:chemistry / Q000378:metabolism*; D012329:RNA, Bacterial / Q000032:analysis; D012475:Salmonella / Q000235:genetics / Q000302:isolation & purification; D012680:Sensitivity and Specificity
chemical_list: D009821:Oils; D012329:RNA, Bacterial; D012313:RNA; D004247:DNA