title: On-line coupling of sample preconcentration by LVSEP with gel electrophoretic separation on T-channel chips.
abstract: To achieve an on-line coupling of the sample preconcentration by a large-volume sample stacking with an electroosmotic flow pump (LVSEP) with microchip gel electrophoresis (MCGE), a sample solution, a background solution for LVSEP and a sieving solution for MCGE were loaded in a T-form channel and three reservoirs on PDMS microchips. By utilizing the difference in the flow resistance of the two channels, a low-viscosity sample and a viscous polymer solution were easily introduced into the LVSEP and MCGE channels, respectively. Fluorescence imaging of the sequential LVSEP-MCGE processes clearly demonstrated that a faster stacking of anionic fluorescein and successive introduction into the MCGE channel can be carried out on the T-channel chip. To evaluate the preconcentration performance, a conventional MCZE analysis of fluorescein on the cross-channel chip was compared with LVSEP-MCGE on the short T-channel chip, and as a result that the value of sensitive enhancement factor (SEF) was estimated to be 370. The repeatability of the peak height was good with the RSD value of 3.2%, indicating the robustness of the enrichment performance. In the successive LVSEP-MCGE analysis of φX174/HaeIII digest, the DNA fragments were well enriched to a sharp peak in the LVSEP channel, and they were separated in the MCGE channel, whose electropherogram was well-resembled with that in the conventional MCGE. The values of SEF for the DNA fragments were calculated to be ranging from 74 to 108. Thus, the successive LVSEP-MCGE analysis was effective for both preconcentrating and separating DNA fragments.
authors.affiliation: Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, Hirosaki, Japan.
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Kitagawa
authors.affiliation: Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan.
authors.forename: Saeko
authors.initials: S
authors.lastname: Kinami
authors.affiliation: Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, Hirosaki, Japan.
authors.forename: Yuuki
authors.initials: Y
authors.lastname: Takegawa
authors.affiliation: Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, Hirosaki, Japan.
authors.forename: Isoshi
authors.initials: I
authors.lastname: Nukatsuka
authors.affiliation: Department of Applied Chemistry, Osaka Prefecture University Graduate School of Engineering, Sakai, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Sueyoshi
authors.affiliation: Laboratory for Integrated Biodevice Unit, Quantitative Biology Center, RIKEN, Suita, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kawai
authors.affiliation: Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Otsuka
mesh_terms: D004247:DNA / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D053841:Electroosmosis / Q000295:instrumentation / Q000379:methods*; D046209:Electrophoresis, Microchip / Q000295:instrumentation / Q000379:methods*; D005456:Fluorescent Dyes / Q000032:analysis / Q000737:chemistry; D015203:Reproducibility of Results; D014783:Viscosity
chemical_list: D005456:Fluorescent Dyes; D004247:DNA
keywords: DNA; Gel electrophoresis; Microchip electrophoresis; On-line sample preconcentration