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

An adaptive real ‐time 3D single particle tracking method is demonstrated which captures the heterogeneous dynamics of single particles with high spatiotemporal resolution. This adaptive microscope, which adjusts the tracking parameters in real time for different diffusive speeds, is applied to monitoring viral landing events at the cell membrane, enabling direct measurement of the first viral contacts with the cell surface. AbstractHere, 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 paramet ers 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,...

Source: Small - September 16, 2019 Category: Nanotechnology Authors: Shangguo Hou, Kevin Welsher Tags: Full Paper Source Type: research