Capillary electrophoresis speed

Miniaturized columns have provided a decisive advantage in speed. Uracil, phenol, and benzyl alcohol were separated in 20 seconds by CEC in an 18 mm column with a propyl reversed phase.29 A19 cm electrophoretic channel was etched into a glass wafer, filled with a y-cyclodextrin buffer, and used to resolve chiral amino acids from a meteorite in 4 minutes.30 A 6 cm channel equipped with a syringe pump to automate sample derivatization was used to separate amino acids modified with fluorescein isothiocyanate.31 Nanovials have been used to perform tryptic digests on the 15 nL scale for subsequent separation on capillary Electrophoresis.32 A microcolumn has also been used to generate fractions representing time-points of digestion from a 40 pL sample.33 A disposable nanoelectrospray emitter has been... 

In E. Coli bacterial lysates, the proteome (i.e., the full array of proteins produced) was analyzed by isoelectric focusing and mass spectrometry.97 A comparison of capillary electrophoretic separation and slab gel separation of a recombinant monoclonal antibody demonstrated that the precision, robustness, speed, and ease-of-use of CE were superior.98 Seventy-five proteins from the yeast ribosome were analyzed and identified by capillary electrophoresis coupled with MS/MS tandem mass spectrometry.99 Heavy-chain C-terminal variants of the anti-tumor necrosis factor antibody DE7 have been separated on capillary isoelectric focusing.100 Isoforms differing by about 0.1 pi units represented antibodies with 0,1 or 2 C-terminal lysines. 

Moore, A.W., Jorgenson, J.W. (1993). Study of zone broadening in optically gated high-speed capillary electrophoresis. Anal. Chem. 65, 3550-3560. 

Capillary electrophoresis has also been combined with other analytical methods like mass spectrometry, NMR, Raman, and infrared spectroscopy in order to combine the separation speed, high resolving power and minimum sample consumption of capillary electrophoresis with the selectivity and structural information provided by the other techniques [6]. 

C.S. Effenhauser, A. Manz, and M. Widmer, Glass chips for high-speed capillary electrophoresis separations with submicrometer plate heights. Anal. Chem. 65, 2637-2642 (1993). 

Biomolecular MS and in particular MALDI-TOF-MS (see Sections 2.1.22 and 2.2.1) permit the routine analysis of oligonucleotides up to 70-mers, intact nucleic acids, and the direct detection of DNA products with no primer labels with an increase in analysis speed and mass accuracy especially in contrast to traditional DNA separation techniques such as slab gels or capillary electrophoresis. Applications focus on the characterization of single nucleotide polymorphisms (SNPs) and short tandem repeats (STRs). Precise and accurate gene expression measurements show relative and absolute numbers of target molecules determined independently of the number of PCR cycles. DNA methylation can be studied quantitatively. 

Capillary procedures offer several advantages, including speed, resolution, sensitivity and technical simplicity, compared with the traditional methods on which they were based. An added advantage for iso-electric focusing in capillaries is the fact that it can be performed without a gel, but a coating on the internal surface of the capillary is usually required to reduce electroendosmosis. Similarly, isotachophoresis can be conveniently performed in capillary electrophoresis apparatus. 

Effenhauser, C. S., Paulus, A., Manz, A., and Widmer, H. M. (1994). High-speed separation of antisense oligonucleotides on a micromachined capillary electrophoresis device. Anal. Chem. 66, 2949-2953. 

Based on the first FAB-MS data, we assumed IV and V-2 to be two isomers with a pyrrolemethanol and a pyrroleninone nucleus, respectively (fig. 8), originating from the condensation of A-DHLNL with an oxidized hydroxylysine residue (fig. 9). The proposed formation of IV is a Knorr-Paal condensation, which has been proposed for the formation of an other pyrrolic cross-link analogous to the heme-precursor porphobilinogen (Scott et al., 1981). In addition, both IV and V-2 had migration speeds comparable to HP (III) in capillary electrophoresis. The presence... 

A further improvement of the more traditional slab gel analysis is the use of high-performance capillary electrophoresis (HPCE), which combines the separation power of high-performance liquid chromatography (HPLC) with the selectivity and speed of conventional gel electrophoresis. However, as HPCE separations are often performed using fused silica capillaries the positively charged histone molecules... 

Electrophoresis has been used for a long time as one of the most important separation principles in analytical biochemistry. In particular, it has been applied to the separation of DNA and DNA components. Electrophoretical techniques have predominated in this field for decades and will continue to do so in the future. The advent of capillary electrophoresis (CE) has boosted the development of electrophoretic techniques, because it opened access to higher sensitivity, better resolution, and greater speed of separation (1-3). 

The introduction of narrow-bore capillaries into electrophoresis started a tremendous evolution of analytical power as well as speed and reliability of electrophoretic methods. Besides an impressive diversification of analytical procedures, it became evident in recent years that capillary electrophoresis provides very suitable methods for the characterization and quantification of molecular interactions. 

Finally, when RPC methods are used in preparative studies with peptides, the opportunity routinely exists for subsequent analysis of the recovered fractions by a variety of analytical methods including high-speed RP-HPLC, HP-IEX, HP-HILIC, or HP-IMAC, zonal or micellar electrokinetic high-performance capillary electrophoresis (HP-CZE and MECK-CZE), capillary electrochromatography (CEC), or capillary isotachophoresis. The combination of the RPC information, drawn from the In k versus i > plots, with the data derived from on-line spectroscopic detection thus readily provides a comprehensive opportunity to assess the purity of an isolated peptide, many of the physicochemical features of the interaction, as well as a means to optimize the resolution in the RPC separation. 

During a capillary electrophoresis experiment it is observed that if the capillary contains an acrylamide gel as well as an electrolyte then the speed of migration is slowed by the mechanical effects of filtration through the gel. This is particularly significant for larger molecules. The following relationship can be considered as proven ... 

Capillary electrophoresis is a new technique that combines the high resolving power of electrophoresis with the speed, versatility, and automation of... 

Since the determination of polymeric anthocyanins is still an open problem, new analytical methods such as capillary electrophoresis and SFC will perhaps make the analysis of these polymeric pigments possible. Due to advantages such as speed and selectivity, it can be assumed that HPLC will stay the method of choice for the analysis of monomeric anthocyanins in the coming years. 

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