title: On-line isotachophoretic preconcentration and gel electrophoretic separation of sodium dodecyl sulfate-proteins on a microchip.
abstract: A microchip for integrated isotachophoretic (ITP) preconcentration with gel electrophoretic (GE) separation to decrease the detectable concentration of sodium dodecyl sulfate (SDS)-proteins was developed. Each channel of the chip was designed with a long sample injection channel to increase the sample loading and allow stacking the sample into a narrow zone using discontinuous ITP buffers. The pre-concentrated sample was separated in GE mode in sieving polymer solutions. All the analysis steps including injection, preconcentration, and separation of the ITP-GE process were performed continuously, controlled by a high-voltage power source with sequential voltage switching between the analysis steps. Without deteriorating the peak resolution, four SDS-protein analyses with integrated ITP-GE system resulted in a decreased detectable concentration of approximately 40-fold compared to the GE mode only. A good calibration curve for molecular weights of SDS-proteins indicated that the integrated ITP-GE system can be used for qualitative analysis of unknown protein samples.
authors.affiliation: Dalian Institute of Chemical Physics, Graduate School of the Chinese Academy of Sciences, Dalian, PR China.
authors.forename: Huaiqing
authors.initials: H
authors.lastname: Huang
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
authors.forename: Zhongpeng
authors.initials: Z
authors.lastname: Dai
authors.forename: Bingcheng
authors.initials: B
authors.lastname: Lin
mesh_terms: D002138:Calibration; D046209:Electrophoresis, Microchip / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D009862:Online Systems; D011506:Proteins / Q000302:isolation & purification*; D012967:Sodium Dodecyl Sulfate
chemical_list: D011506:Proteins; D012967:Sodium Dodecyl Sulfate