Proteome-on-a-chip: Mirage, or on the horizon?

Abstract

Proteomics has emerged as the next great scientific challenge in the post-genome era. But even the most basic form of proteomics, proteome profiling, i.e., identifying all of the proteins expressed in a given sample, has proven to be a demanding task. The proteome presents unique analytical challenges, including significant molecular diversity, an extremely wide concentration range, and a tendency to adsorb to solid surfaces. Microfluidics has been touted as being a useful tool for developing new methods to solve complex analytical challenges, and, as such, seems a natural fit for application to proteome profiling. In this review, we summarize the recent progress in the field of microfluidics in four key areas related to this application: chemical processing, sample preconcentration and cleanup, chemical separations, and interfaces with mass spectrometry. We identify the bright spots and challenges for the marriage of microfluidics and proteomics, and speculate on the outlook for progress.

Transport phenomena in nanofluidics

“…Until recently, the main focus has been placed on the separation of long DNA molecules ͑Chou et al, Lander et al, 2001͒, limitations in gel electrophoresis ͑Turmel et al, 1990Gygi et al, 2000;Lambert et al, 2005͒, and well-known DNA separation physics ͑Giddings, 1965de Gennes, 1979;Stellwagen et al, 1997;Righetti et al, 2002;Slater et al, 2003͒. The interest in separation techniques for smaller physiologically relevant biomolecules is increasing ͑Corthals et al, 1997; Anderson and Anderson, 1998;Rabilloud, 2002;Freire and Wheeler, 2006͒.…”

Development of an automated digestion and droplet deposition microfluidic chip for MALDI-TOF MS

“…The small sample and reagent requirements, rapid analysis times, high throughput processing capabilities, and low operating costs are among the driving forces for the development of these systems [5][6][7][8]. Different microfluidic devices have been applied to specific aspects of protein processing, in particular, protein purification and separation, protein digestion, and protein identification by mass spectrometry [9].There have been a number of approaches to on-line and off-line matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) integrated to chipbased devices [10][11][12][13][14][15][16][17][18]. The primary advantage of the MALDI approach compared with electrospray ionization (ESI) when coupling to microfluidic chips is the potential for multiplexing [19].…”

“…The small sample and reagent requirements, rapid analysis times, high throughput processing capabilities, and low operating costs are among the driving forces for the development of these systems [5][6][7][8]. Different microfluidic devices have been applied to specific aspects of protein processing, in particular, protein purification and separation, protein digestion, and protein identification by mass spectrometry [9].…”

Performance of HPLC/MS microchips in isocratic and gradient elution modes

“…The ultimate goal is micrototal analysis systems, [4] which additionally offer automation and parallelization to meet the demands of highsample throughput and high-sample complexity typical of screening applications and proteomics workflows. [5,6] Experimental efforts of coupling microfluidic devices to mass spectrometers started a decade ago and are of on-going interest. [7 -9] Microfluidic flow rates are well suited to the requirements of electrospray ionization-mass spectrometry (ESI-MS).…”