Peer Reviewed: Advances in CE/MS.

Recent advances in the study of biomolecular interactions by capillary electrophoresisCapillary electrophoresis (CE) has been abundantly used in the study of molecular interactions owing to such advantages as short analysis time, low sample size requirement, high separation efficiency, and flexible applications. The focus of this paper is to review recent studies and advances (mainly from 1998 to now) in biomolecular interactions using CE. Five CE modes: zone migration CE, affinity CE, frontal analysis (FA), Hummel-Dreyer (HD) and vacancy peak (VP) are cited and compared. Quantitative aspects of the thermodynamics and kinetics of biomolecular interaction are reviewed. Several biomolecular binding systems, including protein-protein (polypeptide), protein-DNA (RNA), protein(polypeptide)-carbohydrate, protein-small molecule, DNAsmall molecule, small molecule-small molecule, have been well characterized by CE. CE is shown to be a powerful tool for the determination of the binding parameters of various bioaffinity interactions.

Section: Discussionmentioning

confidence: 99%

Recent advances in the study of biomolecular interactions by capillary electrophoresis

Ding

et al. 2004

“…However, as the sample becomes more complicated, MS provides a better alternative for CE detection owing to its high specificity, unambiguous identification of analytes, and m/z separation capability. There have been many practical methods to couple CE with mass spectrometer, and they can be divided into three major approaches: sheathless [7][8][9][10][11][12][13][14], sheath flow [15][16][17], and liquid junction [18][19][20]. Because of its easiness of implementation, sheath flow interface is the method often used in commercial ESI sources.…”

Section: Introductionmentioning

confidence: 99%

Sheathless capillary electrophoresis‐mass spectrometry using a pulsed electrospray ionization source

Chao

Chen

et al. 2006

A sheathless interface has been developed for coupling CE with electrospray IT mass spectrometer. This interface utilized a pulsed ESI source. The use of a pulsed electrospray source allows the use of a sprayer with larger orifice, and thus alleviates the problem of column clogging during conductive coating and CE analysis. A pulsed ESI source operated at 20 Hz and 20% duty cycle was found to produce the optimal signals. For better signals, the maximum ion injection time in the IT mass spectrometer has to be set to a value close to the actual spraying time (10 ms). Using a sprayer with 50 microm od, more stable and enhanced signals were obtained in comparison with continuous CE-ESI-MS under the same flow rate (150 nL/min). The utility of this design is demonstrated with the analysis of synthetic drugs by CE-MS.

“…Foremost is the robust transfer of analytes from the separations (CE) capillary to the inlet of the mass spectrometer via electrospray. Many different types of ESI interfaces have been reported for the coupling of CE to MS [18,[22][23][24][25][26][27][28][29][30][31][32][33][34][35]. In general they fall into three classes: (i) sheathless interfaces, wherein the separations capillary is connected directly to an electrospray emitter (tip), (ii) liquid-junction interfaces, where there is a small liquidfilled gap between the separations capillary and the emitter, and (iii) sheath-flow interfaces, wherein the end of the separations capillary is enclosed within another capillary through which flows a constant supply of sheath liquid.…”

Section: Introductionmentioning

confidence: 99%

An automated, sheathless capillary electrophoresis‐mass spectrometry platform for discovery of biomarkers in human serum

Sassi¹,

Andel²,

Bitter³

et al. 2005

An automated, sheathless capillary electrophoresis-mass spectrometry platform for discovery of biomarkers in human serumA capillary electrophoresis-mass spectrometry (CE-MS) method has been developed to perform routine, automated analysis of low-molecular-weight peptides in human serum. The method incorporates transient isotachophoresis for in-line preconcentration and a sheathless electrospray interface. To evaluate the performance of the method and demonstrate the utility of the approach, an experiment was designed in which peptides were added to sera from individuals at each of two different concentrations, artificially creating two groups of samples. The CE-MS data from the serum samples were divided into separate training and test sets. A pattern-recognition/feature-selection algorithm based on support vector machines was used to select the mass-to-charge (m/z) values from the training set data that distinguished the two groups of samples from each other. The added peptides were identified correctly as the distinguishing features, and pattern recognition based on these peptides was used to assign each sample in the independent test set to its respective group. A twofold difference in peptide concentration could be detected with statistical significance (pvalue , 0.0001). The accuracy of the assignment was 95%, demonstrating the utility of this technique for the discovery of patterns of biomarkers in serum.