Recent innovations in protein separation on microchips by electrophoretic methods: An update

Lab‐on‐a‐chip electrophoresis is becoming increasingly useful for protein analysis, thanks to recent developments in this field. This review is an update of the review we published at the start of 2008 [Peng, Y., Pallandre, A., Tran, N. T., Taverna, M., Electrophoresis 2008, 29, 156–177]. The superiority of polymers for the manufacture of analytical microchips has been confirmed. This trend implies several modifications to the processes previously used with glass/silicon chips and requires a better understanding of the interfacial phenomena of these materials. Significant progress in chip‐based techniques for protein analysis has been made in the last 2 years. In addition to advances in traditional electrokinetic modes, counter‐flow gradient focusing techniques have emerged as useful methods not only for separation, but also for the online preconcentration of samples. This review, with more than 175 references, presents recent advances and novel strategies for EOF measurement, surface treatment, sample pretreatment, detection and innovations relating to the different modes of separation.

[1]  A. Woolley,et al.  Field gradient electrophoresis , 2005, Electrophoresis.

[2]  A. Cifuentes,et al.  Recent advances in the application of capillary electromigration methods for food analysis , 2006, Electrophoresis.

[3]  Uwe Karst,et al.  Recent developments in optical detection methods for microchip separations , 2006, Analytical and bioanalytical chemistry.

[4]  A. Timerbaev,et al.  High-sensitivity capillary and microchip electrophoresis using electrokinetic supercharging preconcentration. Insight into the stacking mechanism via computer modeling. , 2009, Journal of chromatography. A.

[5]  D. Belder,et al.  Label-free fluorescence detection in capillary and microchip electrophoresis , 2009, Analytical and bioanalytical chemistry.

[6]  Hongkai Wu,et al.  Convenient method for modifying poly(dimethylsiloxane) with poly(ethylene glycol) in microfluidics. , 2009, Analytical chemistry.

[7]  O. Chailapakul,et al.  Influence of polymer structure on electroosmotic flow and separation efficiency in successive multiple ionic layer coatings for microchip electrophoresis , 2008, Electrophoresis.

[8]  D. Kohlheyer,et al.  Miniaturizing free‐flow electrophoresis – a critical review , 2008, Electrophoresis.

[9]  Jikun Liu,et al.  Microfluidic 2-D PAGE using multifunctional in situ polyacrylamide gels and discontinuous buffers. , 2009, Lab on a chip.

[10]  R. Zare,et al.  Use of a mixture of n-dodecyl-beta-D-maltoside and sodium dodecyl sulfate in poly(dimethylsiloxane) microchips to suppress adhesion and promote separation of proteins. , 2007, Analytical chemistry.

[11]  H. Lauer,et al.  Capillary zone electrophoresis of proteins in untreated fused silica tubing , 1986 .

[12]  Youyuan Peng,et al.  Recent innovations in protein separation on microchips by electrophoretic methods , 2008, Electrophoresis.

[13]  Ursula Bilitewski,et al.  Biochemical analysis with microfluidic systems , 2003, Analytical and bioanalytical chemistry.

[14]  Chun Yang,et al.  Numerical modeling of Joule heating‐induced temperature gradient focusing in microfluidic channels , 2008, Electrophoresis.

[15]  G. Her,et al.  Chip‐CE/MS using a flat low‐sheath‐flow interface , 2008, Electrophoresis.

[16]  Martin Pumera,et al.  Contactless conductivity detection for microfluidics: designs and applications. , 2007, Talanta.

[17]  K. Bartle,et al.  Towards a miniaturised system for dynamic field gradient focused separation of proteins. , 2004, Journal of chromatography. A.

[18]  Jing Li,et al.  Microchip micellar electrokinetic chromatography based on one functionalized ionic liquid and its excellent performance on proteins separation. , 2008, Journal of chromatography. A.

[19]  Hongyuan Chen,et al.  EOF measurement by detection of a sampling zone with end‐channel amperometry in microchip CE , 2006, Electrophoresis.

[20]  Anup K Singh,et al.  On-chip isoelectric focusing using photopolymerized immobilized pH gradients. , 2008, Analytical chemistry.

[21]  J. Ramsey,et al.  Fully integrated glass microfluidic device for performing high-efficiency capillary electrophoresis and electrospray ionization mass spectrometry. , 2008, Analytical chemistry.

[22]  N. Kaji,et al.  Channel wall coating on a poly‐(methyl methacrylate) CE microchip by thermal immobilization of a cellulose derivative for size‐based protein separation , 2007, Electrophoresis.

[23]  C. Ivory.  Several new electrofocusing techniques , 2007, Electrophoresis.

[24]  A. Woolley,et al.  Phase-changing sacrificial layers in microfluidic devices: adding another dimension to separations , 2009, Analytical and bioanalytical chemistry.

[25]  Xuefei Sun,et al.  Adsorption-resistant acrylic copolymer for prototyping of microfluidic devices for proteins and peptides. , 2007, Analytical chemistry.

[26]  Liang Zhao,et al.  Measurement of electroosmotic flow in capillary and microchip electrophoresis. , 2007, Journal of chromatography. A.

[27]  Robert T Kennedy,et al.  Multiplexed detection and applications for separations on parallel microchips , 2008, Electrophoresis.

[28]  Hong Chen,et al.  Two‐dimensional protein separation in microfluidic devices , 2009, Electrophoresis.

[29]  James W. Jorgenson,et al.  Zone electrophoresis in open-tubular glass capillaries , 1981 .

[30]  K. Witt,et al.  Prediction and understanding system peaks in capillary zone electrophoresis. , 2007, Journal of separation science.

[31]  N. Kaji,et al.  Dynamic coating using methylcellulose and polysorbate 20 for nondenaturing electrophoresis of proteins on plastic microchips , 2007, Electrophoresis.

[32]  Influence of transport properties in electric field gradient focusing. , 2007, Journal of chromatography. A.

[33]  Jie Wu,et al.  Low-voltage dynamic control for DC electroosmotic devices , 2009 .

[34]  Bingcheng Lin,et al.  Electrophoretic separations on microfluidic chips , 2007, Journal of Chromatography A.

[35]  Versatile method for electroosmotic flow measurements in microchip electrophoresis. , 2009, Journal of chromatography. A.

[36]  A. Woolley,et al.  Programed elution and peak profiles in electric field gradient focusing , 2008, Electrophoresis.

[37]  K. Bartle,et al.  Electrophoretic field gradient focusing: An investigation of the experimental parameters , 2008, Electrophoresis.

[38]  B. Balgley,et al.  Selective enrichment and ultrasensitive identification of trace peptides in proteome analysis using transient capillary isotachophoresis/zone electrophoresis coupled with nano‐ESI‐MS , 2006, Electrophoresis.

[39]  M. Taverna,et al.  LIF detection of peptides and proteins in CE , 2007, Electrophoresis.

[40]  Jing Li,et al.  Sensitive, label‐free protein assay using 1‐ethyl‐3‐methylimidazolium tetrafluoroborate‐supported microchip electrophoresis with laser‐induced fluorescence detection , 2008, Electrophoresis.

[41]  V. Tandon,et al.  Zeta potential and electroosmotic mobility in microfluidic devices fabricated from hydrophobic polymers: 2. Slip and interfacial water structure , 2008, Electrophoresis.

[42]  R. Kostiainen,et al.  Fully microfabricated and integrated SU-8-based capillary electrophoresis-electrospray ionization microchips for mass spectrometry. , 2007, Analytical Chemistry.

[43]  So-Hee Park,et al.  Electrophoretic total analysis of trace tetracycline antibiotics in a microchip with amperometry , 2009, Electrophoresis.

[44]  N. Kaji,et al.  Dynamic cross-linking effect of Mg2+ to enhance sieving properties of low-viscosity poly(vinylpyrrolidone) solutions for microchip electrophoresis of proteins. , 2008, Analytical chemistry.

[45]  Zhifang Fan,et al.  Device fabrication and integration with photodefinable microvalves for protein separation , 2007 .

[46]  W. Verboom,et al.  Optical sensing systems for microfluidic devices: a review. , 2007, Analytica chimica acta.

[47]  Hongyuan Chen,et al.  Low EOF rate measurement based on constant effective mobility in microchip CE , 2007, Electrophoresis.

[48]  Yong Qiu,et al.  Whole column fluorescence imaging on a microchip by using a programmed organic light emitting diode array as a spatial-scanning light source and a single photomultiplier tube as detector. , 2007, Lab on a chip.

[49]  Xuefei Sun,et al.  Fabrication of conductive membrane in a polymeric electric field gradient focusing microdevice. , 2006, Analytical chemistry.

[50]  Microchip capillary electrophoresis. , 2009, Methods in molecular biology.

[51]  D. Ross,et al.  Quantitative temperature gradient focusing performed using background electrolytes at various pH values , 2006, Electrophoresis.

[52]  Tomohisa Kawabata,et al.  “Electrokinetic Analyte Transport Assay” for α‐fetoprotein immunoassay integrates mixing, reaction and separation on‐chip , 2008, Electrophoresis.

[53]  C. Ivory,et al.  Characterization of voltage degradation in dynamic field gradient focusing , 2008, Electrophoresis.

[54]  Pamela Lane,et al.  Bacterial characterization using protein profiling in a microchip separations platform , 2007, Electrophoresis.

[55]  W. Heineman,et al.  On-line sample preconcentration using field-amplified stacking injection in microchip capillary electrophoresis. , 2006, Analytical chemistry.

[56]  E. Kenndler,et al.  Electrophoresis in synthetic organic polymer capillaries: variation of electroosmotic velocity and .zeta. potential with pH and solvent composition , 1992 .

[57]  K. Otsuka,et al.  Recent progress of online sample preconcentration techniques in microchip electrophoresis. , 2008, Journal of separation science.

[58]  Electrokinetic instability effects in microchannels with and without nanofilm coatings , 2008, Electrophoresis.

[59]  Hyun Park,et al.  Direct analysis of trace phenolics with a microchip: in-channel sample preconcentration, separation, and electrochemical detection. , 2006, Analytical chemistry.

[60]  Shuang Yang,et al.  Optimization of sample transfer in two-dimensional microfluidic separation systems. , 2008, Lab on a chip.

[61]  Zsolt Tulassay,et al.  Protein microchips in biomedicine and biomarker discovery , 2007, Electrophoresis.

[62]  Matthew S Munson,et al.  Temperature gradient focusing for microchannel separations , 2007, Analytical and bioanalytical chemistry.

[63]  Chun-Che Lin,et al.  Integrated isotachophoretic stacking and gel electrophoresis on a plastic substrate and variations in detection dynamic range , 2008, Electrophoresis.

[64]  J. Beattie.  The intrinsic charge on hydrophobic microfluidic substrates. , 2006, Lab on a chip.

[65]  B. A. Williams,et al.  Fast, accurate mobility determination method for capillary electrophoresis. , 1996, Analytical chemistry.

[66]  J. Jorgenson,et al.  Capillary zone electrophoresis: Effect of physical parameters on separation efficiency and quantitation , 1985 .

[67]  Igor L Medintz,et al.  Microfabricated two-dimensional electrophoresis device for differential protein expression profiling. , 2007, Analytical chemistry.

[68]  B. Gaš,et al.  Determination of cationic mobilities and pKa values of 22 amino acids by capillary zone electrophoresis , 2004, Electrophoresis.

[69]  Changgeng Liu,et al.  Multichannel microchip electrophoresis device fabricated in polycarbonate with an integrated contact conductivity sensor array. , 2007, Analytical chemistry.

[70]  Dietrich Kohlheyer,et al.  Microfluidic high-resolution free-flow isoelectric focusing. , 2007, Analytical chemistry.

[71]  Klavs F Jensen,et al.  Cascaded free-flow isoelectric focusing for improved focusing speed and resolution. , 2007, Analytical chemistry.

[72]  Prashanta Dutta,et al.  Modeling and simulation of IEF in 2‐D microgeometries , 2007, Electrophoresis.

[73]  Sunjung Park,et al.  Generating high peak capacity 2‐D maps of complex proteomes using PMMA microchip electrophoresis , 2008, Electrophoresis.

[74]  K. Shimura.  Recent advances in IEF in capillary tubes and microchips , 2009, Electrophoresis.

[75]  Sergio L C Ferreira,et al.  Separation and preconcentration procedures for the determination of lead using spectrometric techniques: a review. , 2006, Talanta.

[76]  Alberto Escarpa,et al.  Microchips for CE: Breakthroughs in real‐world food analysis , 2008, Electrophoresis.

[77]  I. Lazar,et al.  Recent advances in capillary and microfluidic platforms with MS detection for the analysis of phosphoproteins , 2009, Electrophoresis.

[78]  E. Wang,et al.  Ionic liquid‐assisted PDMS microchannel modification for efficiently resolving fluorescent dye and protein adsorption , 2007, Electrophoresis.

[79]  G. Allmaier,et al.  Comparing the applicability of CGE‐on‐the‐chip and SDS‐PAGE for fast pre‐screening of mouse serum samples prior to proteomics analysis , 2008, Electrophoresis.

[80]  Jikun Liu,et al.  Surface modification of glycidyl-containing poly(methyl methacrylate) microchips using surface-initiated atom-transfer radical polymerization. , 2008, Analytical Chemistry.

[81]  Jianlong Zhao,et al.  Microchip‐based small, dense low‐density lipoproteins assay for coronary heart disease risk assessment , 2008, Electrophoresis.

[82]  Gang Chen,et al.  Fabrication, modification, and application of poly(methyl methacrylate) microfluidic chips , 2008, Electrophoresis.

[83]  G. D. de Jong,et al.  Recent developments in capillary isoelectric focusing. , 2008, Journal of chromatography. A.

[84]  A. Woolley,et al.  In‐channel atom‐transfer radical polymerization of thermoset polyester microfluidic devices for bioanalytical applications , 2007, Electrophoresis.

[85]  Gabriel Peltre,et al.  Isoelectric focusing in an ordered micropillar array , 2008, Electrophoresis.

[86]  Xiaoyu Chen,et al.  Microchip assays for screening monoclonal antibody product quality , 2008, Electrophoresis.

[87]  R. Kostiainen,et al.  Performance of SU-8 microchips as separation devices and comparison with glass microchips. , 2007, Analytical chemistry.

[88]  Rinse and evaporation coating of poly(methyl methacrylate) microchip for separation of sodium dodecyl sulfate-protein complex. , 2008, Journal of chromatography. A.

[89]  Xiaomi Xu,et al.  Electrochemical and optical detectors for capillary and chip separations. , 2007, Trends in analytical chemistry : TRAC.

[90]  Yi Li,et al.  Phase-changing sacrificial materials for interfacing microfluidics with ion-permeable membranes to create on-chip preconcentrators and electric field gradient focusing microchips. , 2006, Analytical chemistry.

[91]  Identification of viruses using microfluidic protein profiling and Bayesian classification. , 2008, Analytical chemistry.

[92]  Takehiko Kitamori,et al.  Biological cells on microchips: new technologies and applications. , 2007, Biosensors & bioelectronics.

[93]  A. Barron,et al.  Size‐based protein separations by microchip electrophoresis using an acid‐labile surfactant as a replacement for SDS , 2009, Electrophoresis.

[94]  Alberto Escarpa,et al.  CE microchips: An opened gate to food analysis , 2007, Electrophoresis.

[95]  Ring-Ling Chien,et al.  Controlling data quality and reproducibility of a high-sensitivity immunoassay using isotachophoresis in a microchip. , 2008, Analytical chemistry.

[96]  S. Wren,et al.  Characterisation of electroosmotic flow in capillary electrochromatography columns. , 2001, Journal of chromatography. A.

[97]  J. Kong,et al.  Construction of a biomimetic surface on microfluidic chips for biofouling resistance. , 2006, Analytical chemistry.

[98]  D. Ross,et al.  Counter‐flow gradient electrofocusing , 2007, Electrophoresis.

[99]  A. Woolley,et al.  Electric field gradient focusing. , 2005, Journal of separation science.

[100]  W Thormann,et al.  Modeling of electroosmotic and electrophoretic mobilization in capillary and microchip isoelectric focusing. , 2007, Journal of chromatography. A.

[101]  B. A. Williams,et al.  Determination of accurate electroosmotic mobility and analyte effective mobility values in the presence of charged interacting agents in capillary electrophoresis. , 1997, Analytical chemistry.

[102]  Noritada Kaji,et al.  Online preconcentration by transient isotachophoresis in linear polymer on a poly(methyl methacrylate) microchip for separation of human serum albumin immunoassay mixtures. , 2007, Analytical chemistry.

[103]  Yu-Cheng Lin,et al.  Using an electro-microchip, a nanogold probe, and silver enhancement in an immunoassay. , 2009, Biosensors & bioelectronics.

[104]  Kenneth S. Breuer,et al.  Microscale Diagnostic Techniques , 2005 .

[105]  H. Tolley,et al.  Tandem electric field gradient focusing system for isolation and concentration of target proteins. , 2006, Journal of chromatography. A.

[106]  M. Burns,et al.  Low-power concentration and separation using temperature gradient focusing via Joule heating. , 2006, Analytical chemistry.

[107]  Steven A Soper,et al.  High resolution DNA separations using microchip electrophoresis. , 2007, Journal of separation science.

[108]  Chien-Fu Chen,et al.  Polymer microchips integrating solid-phase extraction and high-performance liquid chromatography using reversed-phase polymethacrylate monoliths. , 2009, Analytical chemistry.

[109]  Koji Otsuka,et al.  One-step immobilization of cationic polymer onto a poly(methyl methacrylate) microchip for high-performance electrophoretic analysis of proteins , 2006 .

[110]  Kermit K. Murray,et al.  Microfluidic chips for mass spectrometry-based proteomics. , 2009, Journal of mass spectrometry : JMS.

[111]  Detlev Belder,et al.  Surface modification in microchip electrophoresis , 2003, Electrophoresis.

[112]  R. Zare,et al.  Current-monitoring method for measuring the electroosmotic flow rate in capillary zone electrophoresis , 1988 .

[113]  W. Nelson,et al.  Zeta potential and electroosmotic mobility in microfluidic devices fabricated from hydrophobic polymers: 1. The origins of charge , 2008, Electrophoresis.

[114]  Steven A Soper,et al.  Two-dimensional electrophoretic separation of proteins using poly(methyl methacrylate) microchips. , 2006, Analytical chemistry.

[115]  Radoslaw Mazurczyk,et al.  Application of microfluidic chip with integrated optics for electrophoretic separations of proteins. , 2007, Journal of chromatography. B, Analytical technologies in the biomedical and life sciences.

[116]  T. S. Stevens,et al.  Electroosmotic propulsion of eluent through silica-based chromatographic media , 1983 .

[117]  D. Ross,et al.  Finite sample effect in temperature gradient focusing. , 2007, Lab on a chip.

[118]  H. Tolley,et al.  Equilibrium gradient methods with nonlinear field intensity gradient: a theoretical approach. , 2002, Analytical chemistry.

[119]  F. Everaerts,et al.  System peaks in capillary zone electrophoresis : what are they and where are they coming from? , 1997 .

[120]  J. Findlay,et al.  Electrophoretic field gradient focusing with on-column detection by fluorescence quenching. , 2009, The Analyst.

[121]  A. Manz,et al.  Miniaturized total chemical analysis systems: A novel concept for chemical sensing , 1990 .

[122]  Jin Ho Kim,et al.  Surface modification of poly(dimethylsiloxane) microchannels , 2003, Electrophoresis.

[123]  F. Švec.  Less common applications of monoliths: preconcentration and solid-phase extraction. , 2006, Journal of chromatography. B, Analytical technologies in the biomedical and life sciences.

[124]  Greg J. Sommer,et al.  IEF in microfluidic devices , 2009, Electrophoresis.

[125]  N. Allbritton,et al.  Separations in poly(dimethylsiloxane) microchips coated with supported bilayer membranes. , 2008, Analytical Chemistry.

[126]  Prashanta Dutta,et al.  Effects of ampholyte concentration on protein behavior in on‐chip isoelectric focusing , 2008, Electrophoresis.

[127]  Jing-Juan Xu,et al.  In-situ grafting hydrophilic polymer on chitosan modified poly(dimethylsiloxane) microchip for separation of biomolecules. , 2007, Journal of chromatography. A.

[128]  Jean-Louis Viovy,et al.  Surface treatment and characterization: Perspectives to electrophoresis and lab‐on‐chips , 2006, Electrophoresis.

[129]  Shaurya Prakash,et al.  Water-vapor plasma-based surface activation for trichlorosilane modification of PMMA. , 2006, Langmuir : the ACS journal of surfaces and colloids.

[130]  M. Gaitan,et al.  Temperature measurement in microfluidic systems using a temperature-dependent fluorescent dye. , 2001, Analytical chemistry.

[131]  David M. Jameson,et al.  Resolution of the pH-dependent heterogeneous fluorescence decay of tryptophan by phase and modulation measurements , 1981 .

[132]  P. Dutta,et al.  Isotachophoresis of proteins in a networked microfluidic chip: Experiment and 2‐D simulation , 2007, Electrophoresis.

[133]  N. Kaji,et al.  Poly(methylmethacrylate) Microchip Electrophoresis of Proteins Using Linear-poly(acrylamide) Solutions as Separation Matrix , 2008, Analytical sciences : the international journal of the Japan Society for Analytical Chemistry.

[134]  J. Shim,et al.  Dispersion of protein bands in a horseshoe microchannel during IEF , 2009, Electrophoresis.

[135]  D. Belder,et al.  Impact of laser excitation intensity on deep UV fluorescence detection in microchip electrophoresis , 2008, Electrophoresis.

[136]  Champak Das,et al.  Dynamic coating for protein separation in cyclic olefin copolymer microfluidic devices , 2008 .

[137]  Steven A Soper,et al.  Poly(methyl methacrylate) microchip affinity capillary gel electrophoresis of aptamer–protein complexes for the analysis of thrombin in plasma , 2008, Electrophoresis.

[138]  Amy E Herr,et al.  Microfluidic immunoassays as rapid saliva-based clinical diagnostics , 2007, Proceedings of the National Academy of Sciences.

[139]  L. Locascio,et al.  Microfluidic temperature gradient focusing. , 2002, Analytical chemistry.

[140]  E. Hilder,et al.  Porous polymer monoliths for extraction: diverse applications and platforms. , 2008, Journal of separation science.

[141]  Jingcheng Wang,et al.  Application of poly(dimethylsiloxane)/glass microchip for fast electrophoretic separation of serum small, dense low-density lipoprotein. , 2009, Journal of chromatography. A.

[142]  Janusz Pawliszyn,et al.  Integration of dialysis membranes into a poly(dimethylsiloxane) microfluidic chip for isoelectric focusing of proteins using whole-channel imaging detection. , 2008, Analytical chemistry.

[143]  S. J. R. Staton,et al.  Bioanalytical separations using electric field gradient techniques , 2009, Electrophoresis.

[144]  Hideki Kuramitz,et al.  Magnetic microbead-based electrochemical immunoassays , 2009, Analytical and bioanalytical chemistry.

[145]  Shu-Hui Chen,et al.  Photopatterning of tough single‐walled carbon nanotube composites in microfluidic channels and their application in gel‐free separations , 2008, Electrophoresis.

[146]  J. Santiago,et al.  Taylor–Aris dispersion in temperature gradient focusing , 2007, Electrophoresis.

[147]  A. Svatoš,et al.  Chemical modification of polymeric microchip devices. , 2007, Talanta.

[148]  J. Kong,et al.  Deposition of PEG onto PMMA microchannel surface to minimize nonspecific adsorption. , 2006, Lab on a chip.

[149]  Franka Kalman,et al.  Pharmaceutical applications of isoelectric focusing on microchip with imaged UV detection. , 2008, Journal of chromatography. A.

[150]  D. DeVoe,et al.  Polyacrylamide gel plugs enabling 2‐D microfluidic protein separations via isoelectric focusing and multiplexed sodium dodecyl sulfate gel electrophoresis , 2008, Electrophoresis.

[151]  Jay Lee,et al.  Hard top soft bottom microfluidic devices for cell culture and chemical analysis. , 2009, Analytical chemistry.

[152]  Kiyotaka Sakai,et al.  Thermoresponsive protein adsorption of poly(N-isopropylacrylamide)-modified streptavidin on polydimethylsiloxane microchannel surfaces. , 2009, Biosensors & bioelectronics.

[153]  K. Otsuka,et al.  Micellar electrokinetic chromatography on microchips. , 2008, Journal of separation science.

[154]  E. Verpoorte,et al.  A decade of microfluidic analysis coupled with electrospray mass spectrometry: an overview. , 2007, Lab on a chip.

[155]  A. Timperman,et al.  ESI-MS compatible permanent coating of glass surfaces using poly(ethylene glycol)-terminated alkoxysilanes for capillary zone electrophoretic protein separations. , 2006, Analytical Chemistry.

[156]  D. Herold,et al.  Measurement of microalbuminuria using protein chip electrophoresis. , 2008, American journal of clinical pathology.

[157]  Jikun Liu,et al.  Surface modification of polymer microfluidic devices using in‐channel atom transfer radical polymerization , 2008, Electrophoresis.

[158]  Milton L. Lee,et al.  Poly(ethylene glycol)-functionalized polymeric microchips for capillary electrophoresis. , 2009, Analytical chemistry.

[159]  M. Sauer,et al.  Two-photon excited fluorescence detection at 420 nm for label-free detection of small aromatics and proteins in microchip electrophoresis. , 2007, Lab on a chip.

[160]  A. Woolley,et al.  Performance optimization in electric field gradient focusing. , 2009, Journal of chromatography. A.

[161]  Martin Dufva.  Microchips for cell-based assays. , 2009, Methods in molecular biology.

[162]  Microchip free flow isoelectric focusing for protein prefractionation using monolith with immobilized pH gradient. , 2009, Journal of separation science.