Electrophoresis micro

Ro, K.W., Shim, B.C., Lim, K., Hahn, J.H., Integrated light collimating system for extended optical-path-length absorbance detection in microchip-based capillary electrophoresis. Micro Total Analysis Systems, Proceedings 5th pTAS Symposium, Monterey, CA, Oct. 21-25, 2001, 274-276. 

The characterization of the expressed constituent of a VCL is greatly facilitated by the availability of efficient analytical methods such as mass and NMR spectrometries, capillary electrophoresis, micro-HPLC, etc. These can be applied either to the isolated constituent or even directly to its complex with the target (for the use of mass spectrometry, see [10]). It is clear that the development of micro-methods and laboratory-on-a-chip [11] procedures will have a strong impact on the implementation of combinatorial chemistry approaches. 

Sources Mann, S. E., et al. "Element Specific Detection in Capillary Electrophoresis Using X-ray Fluorescraioe Spectroscopy." Analytical Chemistry 72 (2000), 1754-1758. Miller, T. C., et al. "Capillary Electrophoresis Micro X-ray Ruorescence A Tool for Benchtop Elemental Analysis." Analytical Chemistry 75 (2003), 2048-2053. Figures and captions reproduced with permission from Miller et. al., copyright American Chemical Society 2003. 

Glantz, M. D. Fried, F. Microseparation of tetrazolium salts by paper electrophoresis. Micro-chem. J. 1959, 3, 21 216. 

Polymers have come a long way from parkesine, celluloid and bakelite they have become functional as well as structural materials. Indeed, they have become both at the same time one novel use for polymers depends upon precision micro-embossing of polymers, with precise pressure and temperature control, for replicating electronic chips containing microchannels for capillary electrophoresis and for microfluidics devices or micro-optical components. 

The spectrum of new analytical techniques includes superior separation techniques and sophisticated detection methods. Most of the novel instruments are hyphenated, where the separation and detection elements are combined, allowing efficient use of materials sometimes available only in minute quantities. The hyphenated techniques also significantly increase the information content of the analysis. Recent developments in separation sciences are directed towards micro-analytical techniques, including capillary gas chromatography, microbore high performance liquid chromatography, and capillary electrophoresis. 

Table 1 summarizes several of the experimental methods discussed in this chapter. A need exists for new or revised methods for transport experimentation, particularly for therapeutic proteins or peptides in polymeric systems. An important criterion for the new or revised methods includes in situ sampling using micro techniques which simultaneously sample, separate, and analyze the sample. For example, capillary zone electrophoresis provides a micro technique with high separation resolution and the potential to measure the mobilities and diffusion coefficients of the diffusant in the presence of a polymer. Combining the separation and analytical components adds considerable power and versatility to the method. In addition, up-to-date separation instrumentation is computer-driven, so that methods development is optimized, data are acquired according to a predetermined program, and data analysis is facilitated. 

Jia, L., Liu, B., Terabe, S., Nishioka, T. (2004). Two-dimensional separation method for analysis of bacillus subtilis metabolites via hyphenation of micro-liquid chromatography and capillary electrophoresis. Anal. Chem. 76, 1419-1428. 

Ruchel, R. (1977). Two-dimensional micro-separation technique for proteins and peptides, combining isoelectric focusing and gel gradient electrophoresis. J. Chromatogr. 132, 451 168. 

FIGURE 16.5 Schematic of instrumental setup for 2D micro-RPLC-CZE. A split injection/ flow system is used to deliver a nanoliter per second flow rate to the micro-RP-HPLC column from the gradient LC pump. The HPLC microcolumn has 50 pm i.d. and 76 cm length, and the electrophoresis capillary has 17 pm i.d., L — 25 cm, and/= 15 cm. The valve is air-actuated and controls the flow of flush buffer (reprinted with permission from Analytical Chemistry). 

Microfluidics evolved from micro-analytical methods in capillary format such as capillary electrophoresis, high-performance liquid chromatography, and gas chromatography, and has successfully revolutionized chemical and biochemical... 

The hollow fiber was dipped into dihexyl ether for 5 sec and excess adhering solvent was washed away by ultrasonification in a water bath. Then, 25 fiL of lOmM hydrochloric acid (aqueous, acceptor phase) was injected into the lumen of the hollow fiber with a microsyringe. This activated fiber was placed in the vial containing the donor solution and the vial vibrated at 1500 rpm for 45 min. The entire acceptor solution was flushed into a 200-fJ.L micro insert and subjected to capillary electrophoresis or HPLC detection. For 2 mL extractions, 250 //I. of plasma sample treated with... 

Some coupled systems allow measurement of the main N and P forms (nitrate, ammonia and orthophosphates) [22,27,29], among which is a system based on membrane technology in combination with semi-micro continuous-flow analysis (pCFA) with classical colorimetry. With the same principle (classical colorimetry), another system [30] proposes the measurement of phosphate, iron and sulphate by flow-injection analysis (FIA). These systems are derived from laboratory procedures, as in a recent work [31] where capillary electrophoresis (CE) was used for the separation of inorganic and organic ions from waters in a pulp and paper process. Chloride, thiosulphate, sulphate, oxalate,... 

The -potential of the metal-oxide particles was measured by means of the micro-electrophoresis method (11). 

Wang C., Oleschuk R., Ouchen F., Li J., Thibault R, and Harrison D.J. (2000), Integration of immobilized trypsin bead beds for protein digestion within a micro-fluidic chip incorporating capillary electrophoresis separations and an electrospray mass spectrometry interface, Rapid Commun. Mass Spectrom. 14(15), 1377-1383. 

Micro-tek Scientific (Sunnyvale, CA) Ultra-Plus II CEC, p-LC, capillary zone electrophoresis (CZE) Gradient elution... 

Over the past 40 years, capillary electrophoresis (CE) has advanced significantly as a technique for biomolecular characterization. It has not only passed the transition from a laboratory curiosity to a mature instrumental-based method for micro-scale separation, but also emerged as an indispensable tool in the biotech and pharmaceutical industries. CE has become a method of choice in research and development (R D) for molecular characterization, and in quality control (QC) for the release of the therapeutic biomolecules.In the biopharmaceutical industry, more and more CE methods have been validated to meet International Conference on Harmonization (ICH) requirements. In this chapter, we present real industrial examples to demonstrate the role of CE in R D of pharmaceutical products. The focus in this chapter is on method development analytical control for manufacturing and release of therapeutic proteins and antibodies. 

Nakanishi, H., Nishimoto, T., Kanai, M., Abe, H., Kuyama, H., Yoshida, T., and Arai, A. (1999). Micro-fabrication of quartz microchips for capillary electrophoresis and their analytical performances. Shimadzu Hyoron 56, 3—9. 

Medicinal products, the manufacture of which employs processes which, in the opinion of the EMEA, demonstrate a significant technical advance such as two-dimensional electrophoresis under micro-gravity... 

EM Javerfalk, A Amini, D Westerlund, PE Andren. Chiral separation of local anaesthetics by a capillary electrophoresis/partial-filling technique coupled online to micro-electrospray mass spectrometry. J Mass Spectrom 33 183-186, 1998. 

Although this section provides a brief description of most commonly nsed detectors for HPLC, most of the focus is on a few detection modes. Optical absorbance detectors remain the most widely nsed for HPLC, and are discnssed in some detail. We also focns on flnorescence, condnctivity, and electrochemical detection, as these methods were not widely nsed for HPLC in the past, bnt are especially well suited to micro- and nano-flow instrnments becanse of their high sensitivity in small sample volumes. Mass spectrometry has also come into wide and rontine nse in the last decade, but as it is the subject of another chapter, it will not be fnrther discnssed here. Miniaturization has been particularly important for capillary and chip-based electrophoresis, which often employs sub-nanoliter detection volnmes [36,37]. 

Swinney K, Pennington J, Bomhop DJ. Universal detection in capillary electrophoresis with a micro-interferometric backscatter detector. Analyst 124, 221-225, 1999. 

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