Papers by Keyword: Biological Cell

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Authors: Kozo Taguchi, Keishu Aritoshi, Kyohei Nishimoto, Shun Fukutomi
Abstract: We proposed a simple and low cost dielectrophoretic device to trap and isolate single target cells. The device consisted of a metal coated chemically etched fiber and an AC signal generator. It did not require microfabrication technologies or sophisticated electronics. Using this system, we could easily trap and isolate yeast cells at will. Furthermore, our dielectrophoretic manipulator also could discriminate between live and dead cells by tuning of the applied signal frequency. From these experimental investigations, it was found that our proposed dielectrophoresis tweezers using metal coated chemically etched fiber was a promising tool for the single cell manipulation and isolation.
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Authors: Nobuyuki Watanabe, Kozo Taguchi
Abstract: Biological cell could be trapped by a single laser beam from an optical fiber end inserted at an angle to a sample chamber. We have already developed an optical trapping system. A temperature stabilized 1480nm cw diode laser was used as the light source. The fiber end had a hemispherical micro-lens with 5μm radius of curvature for focusing the laser beam. These trapping fibers were inserted into a sample cell at an angle. The microsphere, 10μm diameter particle (refractive index 1.4), could be trapped. We theoretically analyzed the optical forces exerted on a microsphere by laser beams. The optical force on a microsphere divides itself into two components, the force in the beam axial direction of the light and a transverse force. The transverse optical force acted to pull the sphere back. We investigated the relation between the pulling force and the inserted angle of an optical fiber into a sample chamber. The microsphere is trapped at the point where the horizontal directed optical forces are balanced. We theoretically verified that the inserted angle of an optical fiber into a sample chamber was important parameter. It was found that a small inserted angle produced a weak pulling force.
1053
Authors: Kozo Taguchi, Shinya Imanaka
Abstract: In this paper, chemically etched axicon fibre was proposed for laser trapping of micro-objects dispersed in liquid. We fabricated axicon microlenses on a single-mode bare optical fibre using a selective chemical etching technique. The laser beam from a fibre axicon microlens was strongly focused and optical forces were sufficient to move microorganisms and biological cells without physical contact. From the experimental results, it was found that our proposed fibre axicon microlens is a promising tool for cell trapping and the apex angle of the chemically etched fibre axicon microlens is a very important parameter for laser trapping.
580
Authors: Qing Yi Cui, Ya Wei Wang, Min Bu
Abstract: In order to settle the influence of measuring results of cells with its shape-variety in the examination of biological cell, MCEM (modify co-central ellipse model) is adopted based on the theories of Rayleigh-Debye-Gans, and the changing tendency of scattering phase function of nucleated cells with different body factor, nuclear size and shooting angle are studied. These provide a useful theory foundation for improving the measurement and distinguishing of biological cell.
795
Authors: Nobuyuki Watanabe, Kozo Taguchi
Abstract: Optical trapping is a technique that is used to capture, translate, and manipulate microscopic particles, such as dielectric microspheres and cells. This cell manipulation and examination technology can be integrated on a Lab-on-a-Chip device. We have already developed an optically vibration system. The optical vibration system was formed using a temperature stabilized 1480nm cw diode laser. The output of laser light was coupled into optical fibers, which had optical connectors at these fiber ends. The fiber end had a hemispherical micro-lens with 5μm radius of curvature for focusing the laser beam emerging from the optical fiber end. These trapping fibers were attached to xyz manipulators and were inserted into a sample cell at an angle of 35 degrees. The trapped microsphere, 10μm diameter polystyrene particle (refractive index 1.59), could be optically vibrated by controlling laser power emerging from optical fibers. We theoretically analyzed the optical forces exerted on a microsphere by laser beams. Its operating principle is based upon the conservation of photon momentum carried by the incident laser light on a trapped microsphere. From these theoretical results, we verified that our proposed optical manipulation technique was useful for the manipulation of biological cells.
1059
Authors: Nobuyuki Watanabe, Kozo Taguchi
Abstract: In this paper, we proposed an optical vibration and circulation technique of a microsphere using plural optical flat-top fibres, mounted horizontally on the bottom of a sample chamber, and verify that an optically trapped object can be circulated by controlling laser power emerging from optical fibres without moving the optical fibres. We theoretically analyzed the optical forces exerted on a microsphere, a 10μm diameter polystyrene particle (refractive index 1.59), by laser beams. From these theoretical results, we verify that our proposed optical manipulation technique is useful for the manipulation of biological cells.
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