Ultra-fast two-dimensional microchip electrophoresis using SDS μ-CGE and microemulsion electrokinetic chromatography for protein separations
A poly(methyl methacrylate) microfluidic chip was used to perform a two-dimensional (2-D) separation of a complex protein mixture in short development times. The separation was performed by combining sodium dodecyl sulfate micro-capillary gel electrophoresis (SDS μ-CGE) with microemulsion electrokinetic chromatography (μ-MEEKC), which were used for the first and second dimensions, respectively. Fluorescently labeled Escherichia coli cytosolic proteins were profiled by this 2-D approach with the results compared to a similar 2-D separation using SDS μ-CGE × μ-MEKC (micelle electrokinetic chromatography). The relatively short column lengths (effective length = 10 mm) for both dimensions were used to achieve separations requiring only 220 s of development time. High spot production rates (131 ± 11 spots min−1) and reasonable peak capacities (481 ± 18) were generated despite the fact that short columns were used. In addition, the use of μ-MEEKC in the second dimension was found to produce higher peak capacities compared to μ-MEKC (481 ± 18 for μ-MEEKC and 332 ± 17 for μ-MEKC) due to the higher plate numbers associated with μ-MEEKC.
KeywordsTwo-dimensional electrophoresis Protein profiling E. coli proteins SDS micro-CGE micro-MEEKC PMMA microchip
The authors would like to express their gratitude for financial support of this work by the Louisiana Board of Regents and the National Science Foundation (EPS-0346411). The authors would also like to thank the World Class University (WCU) program for partial financial support of this work.
- 15.Watarai H (1991) Chemistry Letters 391Google Scholar
- 22.Li G, Hu Z (1998) Analyst (Cambridge, United Kingdom) 123:1501Google Scholar
- 30.Hupert M, Guy J, Llopis S, Shadpour H, Rani S, Nikitopoulos D, Soper S (2006) Microfluidics and Nanofluidics ASAP.Google Scholar
- 34.O’Farrell PH (1975) Biol Chem 4007Google Scholar
- 35.Ishihama Y, Schmidt T, Rappsilber J, Mann M, Hartl FU, Kerner MJ, Frishman D (2008) Bmc Genomics 9Google Scholar
- 36.Miseta A, Csutora P (2000) Mol Biol Evol 17:1232Google Scholar
- 38.Liang P, Labedan B, Riley M (2002) Physiol Genomics 9:15Google Scholar
- 54.Terabe S, Matsubara N, Ishihama Y, Okada Y (1992) Elsevier p 23Google Scholar