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Objective-Type Dark-Field Illumination for Scattering from Microbeads

Braslavsky, Ido and Amit, Roee and Ali, B. M. Jaffar and Gileadi, Opher and Oppenheim, Amos and Stavans, Joel (2001) Objective-Type Dark-Field Illumination for Scattering from Microbeads. Applied Optics, 40 (31). pp. 5650-5657. ISSN 0003-6935.

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We introduce a method for detecting and tracking small particles in a solution near a surface. The method is based on blocking the back-reflected illumination beam in an objective-type total internal reflection microscope, leaving unhindered the light scattered by the particles and resulting in dark-field illumination. Using this method, we tracked the motion of 60-nm polystyrene beads with a signal-to-noise ratio of 6 and detected 20-nm gold particles with a signal-to-noise ratio of 5. We illustrate the method’s use by following the Brownian motion of small beads attached by short DNA tethers to a substrate.

Item Type:Article
Additional Information:© Copyright 2001 Optical Society of America Received 22 January 2001; revised manuscript received 6 July 2001. We acknowledge useful conversations with T. Kam, N. Davidson, M. Elbaum, and D. Bensimon and help from Y. Schopen.
Record Number:CaltechAUTHORS:BRAao01
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:4573
Deposited By: Archive Administrator
Deposited On:29 Aug 2006
Last Modified:29 Aug 2014 14:36

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