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High-Precision Tracking with Non-blinking Quantum Dots Resolves Nanoscale Vertical Displacement
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posted on 2012-04-11, 00:00 authored by Kyle Marchuk, Yijun Guo, Wei Sun, Javier Vela, Ning FangNovel non-blinking quantum dots (NBQDs) were utilized
in three-dimensional
super-localization, high-precision tracking applications under an
automated scanning-angle total internal reflection fluorescence microscope
(SA-TIRFM). NBQDs were randomly attached to stationary microtubules
along the radial axis under gliding assay conditions. By automatically
scanning through a wide range of incident angles with different evanescent-field
layer thicknesses, the fluorescence intensity decay curves were obtained.
Fit with theoretical decay functions, the absolute vertical positions
were determined with sub-10-nm localization precision. The emission
intensity profile of the NBQDs attached to kinesin-propelled microtubules
was used to resolve the self-rotation of gliding microtubules within
a small vertical distance of ∼50 nm. We demonstrate the applicability
of NBQDs in high-precision fluorescence imaging experiments.