An Adaptive Real-Time 3D Single Particle Tracking Method for Monitoring Viral First Contacts.

Here, an adaptive real-time 3D single particle tracking method is proposed, which is capable of capturing heterogeneous dynamics. Using a real-time measurement of a rapidly diffusing particle's positional variance, the 3D precision adaptive real-time tracking (3D-PART) microscope adjusts active-feedback parameters to trade tracking speed for precision on demand. This technique is demonstrated first on immobilized fluorescent nanoparticles, with a greater than twofold increase in the lateral localization precision (≈25 to ≈11 nm at 1 ms sampling) as well as a smaller increase in the axial localization precision (≈ 68 to ≈45 nm). 3D-PART also shows a marked increase in the precision when tracking freely diffusing particles, with lateral precision increasing from ≈100 to ≈70 nm for particles diffusing at 4 µm² s^-1 , although with a sacrifice in the axial precision (≈250 to ≈350 nm). This adaptive microscope is then applied to monitoring the viral first contacts of virus-like particles to the surface of live cells, allowing direct and continuous measurement of the viral particle at initial contact with the cell surface.

Duke Scholars

Author Kevin D. Welsher Chemistry