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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Electrophoretic light scattering | 3/3 | https://en.wikipedia.org/wiki/Electrophoretic_light_scattering | reference | science, encyclopedia | 2026-05-05T10:04:29.562309+00:00 | kb-cron |
=== Biophysics === ELS is useful for characterizing information about the surface of proteins. Ware and Flygare (1971) demonstrated that electrophoretic techniques can be combined with laser beat spectroscopy in order to simultaneously determine the electrophoretic mobility and diffusion coefficient of bovine serum albumin. The width of a Doppler shifted spectrum of light that is scattered from a solution of macromolecules is proportional to the diffusion coefficient. The Doppler shift is proportional to the electrophoretic mobility of a macromolecule. From studies that have applied this method to poly (L-lysine), ELS is believed to monitor fluctuation mobilities in the presence of solvents with varying salt concentrations. It has also been shown that electrophoretic mobility data can be converted to zeta potential values, which enables the determination of the isoelectric point of proteins and the number of electrokinetic charges on the surface. Other biological macromolecules that can be analyzed with ELS include polysaccharides. pKa values of chitosans can be calculated from the dependency of electrophoretic mobility values on pH and charge density. Like proteins, the size and zeta potential of chitosans can be determined through ELS. ELS has also been applied to nucleic acids and viruses. The technique can be extended to measure electrophoretic mobilities of large bacteria molecules at low ionic strengths.
=== Nanoparticles === ELS has been used to characterize the polydispersity, nanodispersity, and stability of single-walled carbon nanotubes in an aqueous environment with surfactants. The technique can be used in combination with dynamic light scattering to measure these properties of nanotubes in many different solvents.
== References ==
(1) Surfactant Science Series, Consulting Editor Martin J. Schick Consultant New York, Vol. 76 Electrical Phenomena at Interfaces Second Edition, Fundamentals, Measurements and Applications, Second Edition, Revised and Expanded. Ed by Hiroyuki Ohshima, Kunio Furusawa. 1998. K. Oka and K. Furusawa, Chapter 8 Electrophresis, p. 152 - 223. Marcel Dekker, Inc, (7) B.R. Ware and D.D. Haas, in Fast Method in Physical Biochemistry and Cell Biology. (R.I. Sha'afi and S.M. Fernandez, Eds), Elsevier, New York, 1983, Chap. 8. (9) Ware, B.R; Flygare, W.H (1972). "Light scattering in mixtures of BSA, BSA dimers, and fibrinogen under the influence of electric fields". Journal of Colloid and Interface Science. 39 (3). Elsevier BV: 670–675. doi:10.1016/0021-9797(72)90075-6. ISSN 0021-9797. (10) Josefowicz, J.; Hallett, F. R. (1975-03-01). "Homodyne Electrophoretic Light Scattering of Polystyrene Spheres by Laser Cross-Beam Intensity Correlation". Applied Optics. 14 (3). The Optical Society: 740–742. doi:10.1364/ao.14.000740. ISSN 0003-6935. PMID 20134959. (11) K. Oka, W. Otani, K. Kameyama, M. Kidai, and T. Takagi, Appl. Theor. Electrophor. 1: 273-278 (1990). (12) K. Oka, W. Otani, Y. Kubo, Y. Zasu, and M. Akagi, U.S. Patent Appl. 465, 186: Jpn. Patent H7-5227 (1995). (16) S. Mori and H. Okamoto, Flotation 28: 1 (1980). (in Japanese): Fusen 28(3): 117 (1980). (17) M. Smoluchowski, in Handbuch der Electrizitat und des Magnetismus. (L. Greatz. Ed). Barth, Leripzig, 1921, pp. 379. (18) P. White, Phil. Mag. S 7, 23, No. 155 (1937). (19) S. Komagat, Res. Electrotech. Lab. (Jpn) 348, March 1933. (20) Y. Fukui, S. Yuu and K. Ushiki, Power Technol. 54: 165 (1988).