title: Fabrication of two-weir structure-based packed columns for on-chip solid-phase extraction of DNA.
abstract: Microchip-based packed column SPE of DNA was performed using the microfabricated two-weir structure within a microchannel. We developed two methods to fabricate the two-weir structured glass chips: a "two-side etching/alignment" method and a simplified "one-side/two-step etching" method. The former method required a straightforward alignment step, while the latter approach comprised a simplified wet etching process using paraffin wax as the temporary protective layer. Both methods were convenient and rapid as compared to the previous approaches. Through a reversibly sealed bead-introduction channel, beads can be fed into or out of the chip columns, thus enabling refreshment of the packing materials. Using the proposed chip columns, highly efficient lambda-DNA extractions (average recovery >80%) were performed with good chip-to-chip reproducibility (RSD <10%). The on-chip SPE procedure was completed within 15 min at the flow rate of 3 microL/min and the bulk of the loaded DNA was eluted within a small volume of approximately 8 microL. Application of the microchip-based packed columns was demonstrated by purifying PCR-amplifiable genomic DNA from human hepatocellular carcinoma (HepG2) cells and human whole blood samples.
authors.affiliation: Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, PR China.
authors.forename: Runtao
authors.initials: R
authors.lastname: Zhong
authors.forename: Dayu
authors.initials: D
authors.lastname: Liu
authors.forename: Linfen
authors.initials: L
authors.lastname: Yu
authors.forename: Nannan
authors.initials: N
authors.lastname: Ye
authors.forename: Zhongpeng
authors.initials: Z
authors.lastname: Dai
authors.forename: Jianhua
authors.initials: J
authors.lastname: Qin
authors.forename: Bingcheng
authors.initials: B
authors.lastname: Lin
mesh_terms: D010582:Bacteriophage lambda / Q000737:chemistry; D002460:Cell Line; D004247:DNA / Q000097:blood / Q000302:isolation & purification*; D004279:DNA, Viral / Q000302:isolation & purification; D046209:Electrophoresis, Microchip / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D006801:Humans; D052617:Solid Phase Microextraction / Q000295:instrumentation* / Q000379:methods
chemical_list: D004279:DNA, Viral; D004247:DNA