Electrochromatographic separation of proteins

Basak, Subir K.; Velayudhan, Ajoy; Kohlmann, K.L.; Ladisch, Michael R.

doi:10.1016/0021-9673(94)01276-k

Cited by 26 publications

(16 citation statements)

References 22 publications

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“…Despite the existence of CP (which has been shown relatively early by the electrochromatography of proteins [138,142,143]), this phenomenon is usually overlooked, both in theory and practice. At the same time, retention of charged analytes has strongly puzzled chromatographers.…”

Section: Concentration Polarization In Packed Bedsmentioning

confidence: 93%

Ionic conductance of nanopores in microscale analysis systems: Where microfluidics meets nanofluidics

Höltzel

Tallarek²

2007

J of Separation Science

143

153

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In this tutorial review we illustrate the origin and dependence on various system parameters of the ionic conductance that exists in discrete nanochannels as well as in nanoporous separation and preconcentration units contained as hybrid configurations, membranes, packed beds, or monoliths in microscale liquid phase analysis systems. A particular complexity arises as external electrical fields are superimposed on internal chemical and electrical potential gradients for tailoring molecular transport. It is demonstrated that the variety of geometries in which the microfluidic/nanofluidic interfaces are realized share common, fundamental features of coupled mass and charge transport, but that phenomena behind the key steps in a particular application can be significantly tuned, depending on the morphology of a material. Thus, the understanding of morphology-related transport in internal and external electrical potential gradients is critical to the performance of a device. This addresses a variety of geometries (slits, channels, filters, membranes, random or regular networks of pores, etc.) and applications, e. g., the gating, sensing, preconcentration, and separation in multifunctional miniaturized devices. Inherently coupled mass and charge transport through ion-permselective (charge-selective) microfluidic/nanofluidic interfaces is analyzed with a stepwise-added complexity and discussed with respect to the morphology of the charge-selective spatial domains. Within this scenario, the electrostatics and electrokinetics in microfluidic and nanofluidic channels, as well as the electrohydrodynamics evolving at microfluidic/nanofluidic interfaces, where microfluidics meets nanofluidics, define the platform of central phenomena.

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Section: Concentration Polarization In Packed Bedsmentioning

confidence: 93%

Ionic conductance of nanopores in microscale analysis systems: Where microfluidics meets nanofluidics

Höltzel

Tallarek²

2007

J of Separation Science

143

153

View full text Add to dashboard Cite

show abstract

“…This will produce a selectivity different from that obtained by chromatographic processes alone [1][2][3][4][5][6]. The electrically driven selectivity was successfully applied both in CEC of analytical scale [3] and in preparative electrochromatography [6][7][8][9] for the separation of biological macromolecules. For the latter, its separation power has kept attracting the attention of those interested in enhancing resolution of biological products in large amounts, while its mode is more like pressure-driven electrochromatography [5] used in CEC.…”

Section: Introductionmentioning

confidence: 93%

“…For example, Rudge et al [1,2,8] developed a simple equilibrium model to predict the retention times in the axial electric field SEEC by incorporating the terms that account for the effect of the electric field into conventional chromatography theory. Recently, Tellez and Cole [6] have found that the degree of retention of a biomolecule in the axial electric field SEEC follows its free-solution electrophoretic mobility when the biomolecule is able to enter the gel pores, or follows the ratio of molecular diffusivity to electrophoretic mobility when the biomolecule is excluded by the gel pores.…”

Section: Introductionmentioning

confidence: 99%

“…For the latter, its separation power has kept attracting the attention of those interested in enhancing resolution of biological products in large amounts, while its mode is more like pressure-driven electrochromatography [5] used in CEC. That is, the most preparative electrochromatography of proteins is generally established by applying an external electric field (eEF) in the longitudinal direction of sizeexclusion column [1,2,[6][7][8][9]. In this case, eEF not only improves the mass transfer of electrolytes toward/inside stationary-phase particles [1,2,10,11] but also provides additive retention mechanisms.…”

Section: Introductionmentioning

confidence: 99%

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Oscillatory transverse electric field enhances protein resolution and capacity of size-exclusion chromatography

2006

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Protein separations by a novel size-exclusion electrochromatography (SEEC) are presented. The present SEEC, denoted as pSEEC, was established with an oscillatory low-voltage electric field perpendicular to the mobile-phase streamline. Retention experiments with different proteins indicated that the influence of electric field strength on the partition coefficient is different for different proteins as well as for the same protein under different mobile-phase conditions. These results of protein retention led to the experimental design of protein separations with binary mixtures of BSA and immunoglobulin G (IgG), myoglobin (Myo) and lysozyme (Lys), as well as ovalbumin (Oval) and Myo. The separation results for the binary protein systems sufficiently exhibited the applicability of the pSEEC for various separations in terms of their molecular weights (MWs) as well as pIs. For example, it was possible to separate the gel-excluded proteins (BSA/IgG) as well as gel-permeable and similar-molecular-weight proteins (Myo/Lys) by the pSEEC. Moreover, in the cases of Oval/ Myo, which could be partially separated by size-exclusion chromatography, the use of the pSEEC greatly improved the resolution and the separation became possible at high sample loading. The results indicate that the pSEEC technology is promising for preparative protein separations.

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“…They discussed thermal effects arising from Joule heating and described the separation of bovine hemoglobin and a-lactalbumin with an electric field of 80 V/cm and the partial separation of a-lactalbumin and b-lactoglobulin at 130 V/cm. High voltages (2000± 4000 V) and cooled columns have been used to separate other binary mixtures of proteins [12,13]. Cole and Cabezas [14] monitored the temperature increase in column eluent as a function of applied electric field and explored the effect of the gel degree of cross-linking in the EC of various proteins.…”

Section: Introductionmentioning

confidence: 99%