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Hiroyuki Ohshima - One of the best experts on this subject based on the ideXlab platform.
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Approximate analytic expressions for the Electrophoretic Mobility of spheroidal particles.
Electrophoresis, 2020Co-Authors: Hiroyuki OhshimaAbstract:Approximate analytic expressions are derived for the Electrophoretic Mobility of spheroidal particles (prolate and oblate) carrying low zeta potential in an electrolyte solution under an applied tangential or transverse electric field. The present approximation method, which is based on the observation that the Electrophoretic Mobility of a particle is determined mainly by the distortion of the applied electric field by the presence of the particle. The exact expression for the equilibrium electric potential distribution around the particle, which can be expressed as an infinite sum of spheroidal wave functions, is not needed in the present approximation. The Electrophoretic Mobility values calculated with these approximate expressions for spheroidal particles with constant surface potential or constant surface charge density are in excellent agreement with the exact numerical results of previous reports with the relative errors less than about 4%.
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Dynamic Electrophoretic Mobility of a spherical colloidal particle with a hydrodynamically slipping surface in an oscillating electric field
Colloid and Polymer Science, 2020Co-Authors: Hiroyuki OhshimaAbstract:A theory of the dynamic electrophoresis of a spherical colloidal particle with a slip surface in an oscillating electric field is developed. The slipping length on the particle surface, which is the measure of the degree of the particle surface hydrophobicity, is introduced. The general expression of the particle Electrophoretic Mobility and its approximate analytic expressions for a particle carrying a low zeta potential are derived. Graphical abstract Dynamic Electrophoretic Mobility of a sphere with a slip surface.
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Electrophoretic Mobility of a cylindrical colloidal particle with a slip surface
Colloid and Polymer Science, 2019Co-Authors: Hiroyuki OhshimaAbstract:General expressions of the Electrophoretic Mobility-zeta potential relationship for a cylindrical colloidal particle with a hydrodynamically slipping surface in an aqueous electrolyte solution under a transverse or tangential electric field are obtained on the basis of the Navier boundary condition. Approximate expressions for the Electrophoretic Mobility of cylindrical particles carrying a low zeta potential are derived. As in the case of a sphere, the Electrophoretic Mobility of a cylinder increases with increasing slip length, which characterizes the hydrophobicity of the particle surface.
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Approximate analytic expression for the pH-dependent Electrophoretic Mobility of soft particles
Colloid and Polymer Science, 2016Co-Authors: Hiroyuki OhshimaAbstract:A theory on the Electrophoretic Mobility of a soft particle, i.e., a hard particle covered with an ion-penetrable surface layer of polyelectrolytes (Ohshima J Colloid Interface Sci 163: 474, 1994) is extended by taking into account the degree of dissociation of fixed ionizable groups in the polyelectrolyte surface layer. A simple approximate analytic expression for the pH-dependent Electrophoretic Mobility of a soft particle, carrying monovalent acidic ionizable groups in the polyelectrolyte layer, is derived, which involves the pH-dependent Donnan and surface potentials of a soft particle. With the help of the obtained expression for the pH-dependent Electrophoretic Mobility of soft particles, the Electrophoretic fingerprinting approach can be applied to soft particles.
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Electrophoretic Mobility of a highly charged soft particle relaxation effect
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2011Co-Authors: Hiroyuki OhshimaAbstract:Abstract An approximate analytic expression is derived for the Electrophoretic Mobility of a soft particle, that is, a hard particle of radius a covered with an ion-penetrable surface layer of polyelectrolytes of thickness d in an electrolyte solution of concentration n under conditions at which κa ≫ 1, κd ≫ 1, λa ≫ 1, and λd ≫ 1 (where κ = Debye–Huckel parameter and 1/ λ = softness parameter). The obtained expression is an improvement of a previously derived Mobility expression [Ohshima, J. Colloid Interface Sci., 163 (1994) 474; ibid. 228 (2000) 190] by taking into account the relaxation effect for the region outside the surface charge layer so that it can be applicable for arbitrary values of the density N of fixed-charges in the surface charge layer. It is observed that the Electrophoretic Mobility plotted as a function of N or n exhibits a maximum due to the relaxation effect.
Tzahuei Wang - One of the best experts on this subject based on the ideXlab platform.
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high resolution quantification by charge dominant Electrophoretic Mobility shift of quantum dots
Electrophoresis, 2015Co-Authors: Yi Zhang, Tzahuei WangAbstract:Conjugation of biomolecules to colloidal nanoparticles, such as quantum dots (QDs), often leads to change in Mobility. We discover that linking DNA molecules to quantum dots alters their surface charge density without significantly increasing the hydrodynamic radius, causing a prominent shift in Electrophoretic Mobility. In this study, a high-resolution molecular quantification method named quantification by QDs Electrophoretic Mobility shift (qQEMS) is developed based on the charge-dominant transformation that closely associates DNA quantity to QDs Electrophoretic Mobility. The versatility of qQEMS is demonstrated by a number of quantification assays in which DNA molecules functioned as enzyme substrates, target-specific probes, and competitive charge carriers. qQEMS shows a great potential as a generic and versatile quantification platform for a wide range of applications.
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mapping dna quantity into Electrophoretic Mobility through quantum dot nanotethers for high resolution genetic and epigenetic analysis
ACS Nano, 2012Co-Authors: Yi Zhang, Kelvin J Liu, Tianli Wang, Ie Ming Shih, Tzahuei WangAbstract:Newly discovered nanoparticle properties have driven the development of novel applications and uses. We report a new observation where the Electrophoretic Mobility of a quantum dot/DNA nanoassembly can be precisely modulated by the degree of surface DNA conjugation. By using streptavidin-coated quantum dots (QDs) as nanotethers to gather biotin-labeled DNA into Electrophoretic nanoassemblies, the QD surface charge is modulated and transformed into Electrophoretic Mobility shifts using standard agarose gel electrophoresis. Typical fluorescent assays quantify based on relative intensity. However, this phenomenon uses a novel approach that accurately maps DNA quantity into shifts in relative band position. This property was applied in a QD-enabled nanoassay called quantum dot Electrophoretic Mobility shift assay (QEMSA) that enables accurate quantification of DNA targets down to 1.1-fold (9%) changes in quantity, beyond what is achievable in qPCR. In addition to these experimental findings, an analytical mod...
Takao Tsuda - One of the best experts on this subject based on the ideXlab platform.
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Effect of pressure on Electrophoretic Mobility of polystyrene latex particles.
Electrophoresis, 2004Co-Authors: Akira Sakakibara, Shinya Kitagawa, Takao TsudaAbstract:A capillary electrophoresis system that can apply arbitrary helium gas pressures at both inlet and outlet reservoirs was constructed. The system was used to investigate the effect of pressure on Electrophoretic behavior of polystyrene latex particles. The Electrophoretic Mobility of latex particles was increased with the application of pressure (< 3.0 kgf/cm2). The shrinkage of particle diameter under pressurization was observed using a microscope, however, the magnitude of shrinkage was not enough to explain the increase in Electrophoretic Mobility. Therefore, the application of pressure might increase the electric charge of the latex particle. Since methanol inhibited the enhancement in the Electrophoretic Mobility of the latex particles, water might play an important role in increasing Mobility.
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study of the relationship between Electrophoretic Mobility of the diabetic red blood cell and hemoglobin a1c by using a mini cell electrophoresis apparatus
Electrophoresis, 1999Co-Authors: Shinya Kitagawa, Osamu Nozaki, Takao TsudaAbstract:: A mini-cell electrophoresis system using capillary tubing (50 microm inner diameter, length ca. 10 mm and volume ca. 20 nL) was applied to measure the Electrophoretic Mobility of red blood cells of 89 patients with diabetes on single cell level. A significant negative correlation was observed between hemoglobin A1c and the average Electrophoretic Mobility, with a correlation coefficient of 0.793. By statistically processing the Electrophoretic Mobility of each single red blood cell, it became clear that the reduction of the average value of Electrophoretic Mobility was caused by the reduction of the relative frequency of the red blood cell with high Mobility. The cause of the average reduction was not the shift of Electrophoretic Mobility of all red blood cells to the lower Mobility.
Yi Zhang - One of the best experts on this subject based on the ideXlab platform.
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high resolution quantification by charge dominant Electrophoretic Mobility shift of quantum dots
Electrophoresis, 2015Co-Authors: Yi Zhang, Tzahuei WangAbstract:Conjugation of biomolecules to colloidal nanoparticles, such as quantum dots (QDs), often leads to change in Mobility. We discover that linking DNA molecules to quantum dots alters their surface charge density without significantly increasing the hydrodynamic radius, causing a prominent shift in Electrophoretic Mobility. In this study, a high-resolution molecular quantification method named quantification by QDs Electrophoretic Mobility shift (qQEMS) is developed based on the charge-dominant transformation that closely associates DNA quantity to QDs Electrophoretic Mobility. The versatility of qQEMS is demonstrated by a number of quantification assays in which DNA molecules functioned as enzyme substrates, target-specific probes, and competitive charge carriers. qQEMS shows a great potential as a generic and versatile quantification platform for a wide range of applications.
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mapping dna quantity into Electrophoretic Mobility through quantum dot nanotethers for high resolution genetic and epigenetic analysis
ACS Nano, 2012Co-Authors: Yi Zhang, Kelvin J Liu, Tianli Wang, Ie Ming Shih, Tzahuei WangAbstract:Newly discovered nanoparticle properties have driven the development of novel applications and uses. We report a new observation where the Electrophoretic Mobility of a quantum dot/DNA nanoassembly can be precisely modulated by the degree of surface DNA conjugation. By using streptavidin-coated quantum dots (QDs) as nanotethers to gather biotin-labeled DNA into Electrophoretic nanoassemblies, the QD surface charge is modulated and transformed into Electrophoretic Mobility shifts using standard agarose gel electrophoresis. Typical fluorescent assays quantify based on relative intensity. However, this phenomenon uses a novel approach that accurately maps DNA quantity into shifts in relative band position. This property was applied in a QD-enabled nanoassay called quantum dot Electrophoretic Mobility shift assay (QEMSA) that enables accurate quantification of DNA targets down to 1.1-fold (9%) changes in quantity, beyond what is achievable in qPCR. In addition to these experimental findings, an analytical mod...
Shinya Kitagawa - One of the best experts on this subject based on the ideXlab platform.
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Effect of pressure on Electrophoretic Mobility of polystyrene latex particles.
Electrophoresis, 2004Co-Authors: Akira Sakakibara, Shinya Kitagawa, Takao TsudaAbstract:A capillary electrophoresis system that can apply arbitrary helium gas pressures at both inlet and outlet reservoirs was constructed. The system was used to investigate the effect of pressure on Electrophoretic behavior of polystyrene latex particles. The Electrophoretic Mobility of latex particles was increased with the application of pressure (< 3.0 kgf/cm2). The shrinkage of particle diameter under pressurization was observed using a microscope, however, the magnitude of shrinkage was not enough to explain the increase in Electrophoretic Mobility. Therefore, the application of pressure might increase the electric charge of the latex particle. Since methanol inhibited the enhancement in the Electrophoretic Mobility of the latex particles, water might play an important role in increasing Mobility.
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study of the relationship between Electrophoretic Mobility of the diabetic red blood cell and hemoglobin a1c by using a mini cell electrophoresis apparatus
Electrophoresis, 1999Co-Authors: Shinya Kitagawa, Osamu Nozaki, Takao TsudaAbstract:: A mini-cell electrophoresis system using capillary tubing (50 microm inner diameter, length ca. 10 mm and volume ca. 20 nL) was applied to measure the Electrophoretic Mobility of red blood cells of 89 patients with diabetes on single cell level. A significant negative correlation was observed between hemoglobin A1c and the average Electrophoretic Mobility, with a correlation coefficient of 0.793. By statistically processing the Electrophoretic Mobility of each single red blood cell, it became clear that the reduction of the average value of Electrophoretic Mobility was caused by the reduction of the relative frequency of the red blood cell with high Mobility. The cause of the average reduction was not the shift of Electrophoretic Mobility of all red blood cells to the lower Mobility.