Abstract
The magnetic tweezer is a simple and stable single-molecule manipulation instrument. However, the standard probe-tracking methods have typically failed to reach the high resolution (∼0.3 nm) needed to measure motor protein stepping. In this paper we present a novel illumination geometry, based on an inverted microscope with Hg lamp illumination, that aims to push the resolution of magnetic tweezers to their ultimate thermal limits. Using a metal-coated coverslip and motorized magnets, we convert a standard inverted microscope into a high-resolution magnetic tweezers instrument. Our novel optical geometry reduces the restrictions on magnet design inherent to transmission-based illumination, and does not require fiber-optic coupling. We introduce a high-speed CMOS camera as the optical detector, and demonstrate how an improvement in temporal resolution directly impacts the spatial resolution.
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Acknowledgements
We gratefully acknowledge S. Pennathur and T. Wynne for lending us their hs-CMOS camera, A. Weinberg for manufacturing parts, and F. Freitas for reviewing this manuscript. B.L. acknowledges support from an NSERC PGS-D fellowship.
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© 2013 The Society for Experimental Mechanics
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Lansdorp, B.M., Saleh, O.A. (2013). High Speed Magnetic Tweezers at 10,000fps with Reflected Hg-Lamp Illumination. In: Shaw, G., Prorok, B., Starman, L. (eds) MEMS and Nanotechnology, Volume 6. Conference Proceedings of the Society for Experimental Mechanics Series. Springer, New York, NY. https://doi.org/10.1007/978-1-4614-4436-7_13
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DOI: https://doi.org/10.1007/978-1-4614-4436-7_13
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