A multiplexed magnetic tweezer with precision particle tracking and bi-directional force control
Autor: | Keith C. Johnson, Robin L. Kirkpatrick, Juan C. Vizcarra, Wendy E. Thomas, Hani Mahmoud, Emilie Warner Clemmens |
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Rok vydání: | 2017 |
Předmět: |
0301 basic medicine
Magnetic tweezers Environmental Engineering Materials science Magnetic tweezer Biomedical Engineering 02 engineering and technology Tracking (particle physics) Multiplexing law.invention 03 medical and health sciences Paramagnetism law lcsh:QH301-705.5 Molecular Biology Electromagnet Single molecule force spectroscopy Force spectroscopy Methodology Cell Biology 021001 nanoscience & nanotechnology 030104 developmental biology lcsh:Biology (General) Magnet Particle 0210 nano-technology Biological system |
Zdroj: | Journal of Biological Engineering Journal of Biological Engineering, Vol 11, Iss 1, Pp 1-13 (2017) |
ISSN: | 1754-1611 |
Popis: | Background In the past two decades, methods have been developed to measure the mechanical properties of single biomolecules. One of these methods, Magnetic tweezers, is amenable to acquisition of data on many single molecules simultaneously, but to take full advantage of this "multiplexing" ability, it is necessary to simultaneously incorporate many capabilities that have been only demonstrated separately. Methods Our custom built magnetic tweezer combines high multiplexing, precision bead tracking, and bi-directional force control into a flexible and stable platform for examining single molecule behavior. This was accomplished using electromagnets, which provide high temporal control of force while achieving force levels similar to permanent magnets via large paramagnetic beads. Results Here we describe the instrument and its ability to apply 2–260 pN of force on up to 120 beads simultaneously, with a maximum spatial precision of 12 nm using a variety of bead sizes and experimental techniques. We also demonstrate a novel method for increasing the precision of force estimations on heterogeneous paramagnetic beads using a combination of density separation and bi-directional force correlation which reduces the coefficient of variation of force from 27% to 6%. We then use the instrument to examine the force dependence of uncoiling and recoiling velocity of type 1 fimbriae from Eschericia coli (E. coli) bacteria, and see similar results to previous studies. Conclusion This platform provides a simple, effective, and flexible method for efficiently gathering single molecule force spectroscopy measurements. |
Databáze: | OpenAIRE |
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