Open Channel Electrochromatography on a Microchip

Jacobson, Stephen C.; Hergenröder, Roland; Koutny, Lance; Ramsey, J. Michael

doi:10.1021/ac00086a024

Cited by 318 publications

(144 citation statements)

References 19 publications

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“…Mlcrofluidic systems are finding increasing use in the separation, identification and synthesis of a wide range of chemical and biological species [1,2,3]. Employing transverse channel dimensions in the range from several to a few hundred microns, such systems may permit the large-scale integration of wet anal~lcal methods in a manner analogous to that already achieved in microelectronics.…”

Section: Introductionmentioning

confidence: 99%

Conditions for Similitude between the Fluid Velocity and Electric Field in Electroosmotic Flow

et al. 2000

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Electroosmotic flow is fluid motion driven by an electric field acting on the net fluid charge produced by charge separation at a fluid−solid interface. Under many conditions of practical interest, the resulting fluid velocity is proportional to the local electric field, and the constant of proportionality is everywhere the same. Here we show that the main conditions necessary for this similitude are a steady electric field, uniform fluid and electric properties, an electric Debye layer that is thin compared to any physical dimension, and fluid velocities on all inlet and outlet boundaries that satisfy the Helmholtz−Smoluchowski relation normally applicable to fluid−solid boundaries. Under these conditions, the velocity field can be determined directly from the Laplace equation governing the electric potential, without solving either the continuity or momentum equations. Three important consequences of these conditions are that the fluid motion is everywhere irrotational, that fluid velocities in two-dimensional channels bounded by parallel planes are independent of the channel depth, and that such flows exhibit no dependence on the Reynolds number. Similitude is demonstrated by comparing measured and computed fluid streamlines with computed electric flux lines.

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Section: Introductionmentioning

confidence: 99%

Conditions for Similitude between the Fluid Velocity and Electric Field in Electroosmotic Flow

et al. 2000

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“…A gas chromatograph (9) and a liquid chromatograph (10) have been fabricated on silicon chips, but these devices have not been widely used. Recently, several groups have fabricated individual CE devices on chips and performed capillary zone electrophoresis separations of fluorescent dyes (11,12) and fluorescently labeled amino acids (13)(14)(15). However, it is not known whether high-resolution separations of DNA can be performed with these devices or whether multiple separation channels can be fabricated in a single chip.…”

mentioning

confidence: 99%

Ultra-high-speed DNA fragment separations using microfabricated capillary array electrophoresis chips.

Woolley

Mathies²

1994

Proc. Natl. Acad. Sci. U.S.A.

568

359

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Capillary electrophoresis arrays have been fabricated on planar glass substrates by photolithographic masking and chemical etching techniques. The photolithographically defined channel patterns were etched in a gass substrate, and then capillaries were formed by thermally bonding the etched substrate to a second glass slide. Highresolution electrophoretic separations of OX174 Hae m DNA restriction fragments have been performed with these chips using a hydroxyethyl cellulose sieving matrix in the channels. DNA fragments were fluorescently labeled with dye in the running buffer and detected with a laser-excited, confocal fluorescence system. The effects of variations in the electric field, procedures for injection, and sizes of separation and injection channels (ranging from 30 to 120 #m) have been explored. By use of channels with an effective length of only 3.5 cm, separations of #X174 Hae III DNA fragments from =70 to 1000 bp are complete in only 120 sec. We have also demonstrated high-speed sizing of PCR-amplified HLA-DQa alleles.This work establishes methods for high-speed, highthroughput DNA separations on capillary array electrophoresis chips.Capillary electrophoresis (CE) is a powerful method for DNA sequencing, forensic analysis, PCR product analysis, and restriction fragment sizing (1, 2). CE provides faster and higher-resolution separations than slab gel electrophoresis because higher electric fields can be applied. However, unlike slab gel electrophoresis, conventional CE allows analysis of only one sample at a time. Mathies and Huang (3) have introduced capillary array electrophoresis, in which separations are performed on an array of parallel silica capillaries, and demonstrated that it can be used to perform high-speed, high-throughput DNA sequencing (4, 5) and DNA fragment sizing (6). This method combines the fast electrophoresis times of CE with the ability to analyze multiple samples in parallel. The underlying concept behind the approach was to increase the information density in electrophoresis by miniaturizing the "lane" dimension to =-100 ,um. The further miniaturization of electrophoretic separations to increase the number of lanes, the speed, and the throughput would be valuable in helping to meet the needs of the Human Genome Project (7,8).The electronics industry routinely uses microfabrication to make circuits with features < 1 Aum in size. Microfabrication would allow the production of higher density capillary arrays, whose current density is limited by the capillary outside diameter (4-6). In addition, microfabrication of capillaries on a chip should make it feasible to produce physical assemblies not possible with glass fibers and to link capillaries directly to other devices on the chip. However, few devices for chemical separations have been made by microfabrication technology. A gas chromatograph (9) and a liquid chromatograph (10) have been fabricated on silicon chips, but these devices have not been widely used. Recently, several groups have fabricated individual CE devic...

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“…7 A new attempt to realize analytical chemistry in a liquid micro space has been studied using capillary electrophoresis or capillary electrochromatography. [8][9][10][11][12][13][14][15][16][17][18] Many studies dealing with electrically driven separation techniques on a chip have been reported, such as capillary electrophoresis [8][9][10][11][12] , free-flow electrophoresis 13 , open-channel electrochromatography 14 , micellar electrokinetic capillary chromatography 15 , capillary gel electrophoresis 16 , sizing of DNA restriction fragments 17,18 and so on. The miniaturization of these analytical systems has attracted much interest as a substitute for ordinary capillaries.…”

mentioning

confidence: 99%

Integration of Flow Injection Analysis and Zeptomole-Level Detection of the Fe(II)-o-Phenanthroline Complex

et al. 1999

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Microchannels having a 150×100 µm cross section were fabricated in a quartz glass chip as a component in an integrated flow injection analysis (FIA) system. They were put to use for flow, mixing, reaction, and detection. The reaction system was a chelating reaction of divalent iron ion with o-phenanthroline (o-phen), and a photothermal microscope was applied for the ultra-sensitive detection of the non-fluorescent reaction product. Nano liter levels of solutions were introduced and transported by capillary action and mixed by molecular diffusion. Zeptomole levels of the reaction product were detected quantitatively. This was the first demonstration of an on-chip chemical determination device which integrates the primitive FIA system without using electroosmotic liquid control or fluorometric determination.

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Open Channel Electrochromatography on a Microchip

Abstract: A glass microchip having a channel with a cross section of 5.6

Cited by 318 publications

References 19 publications

Conditions for Similitude between the Fluid Velocity and Electric Field in Electroosmotic Flow

Conditions for Similitude between the Fluid Velocity and Electric Field in Electroosmotic Flow

Ultra-high-speed DNA fragment separations using microfabricated capillary array electrophoresis chips.

Integration of Flow Injection Analysis and Zeptomole-Level Detection of the Fe(II)-o-Phenanthroline Complex

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