Real-time nanomicroscopy via three-dimensional single-particle tracking.

Area of Science:

• Biophysics
• Optical Microscopy
• Cell Biology

Background:

• Accurate tracking of fluorescent particles is crucial for understanding cellular dynamics.
• Existing methods may lack the required spatial or temporal resolution for certain biological investigations.

Purpose of the Study:

• To develop a novel real-time, three-dimensional (3D) tracking method for fluorescent particles.
• To achieve high-resolution tracking and investigate particle interactions with cellular components.

Main Methods:

• Utilized a laser-scanning confocal microscope with an orbiting laser beam focus.
• Employed dual confocal pinholes and a feedback loop for precise particle centering.
• Integrated a dual-color, wide-field fluorescence setup for simultaneous imaging.
• Tracked fluorescent-labeled artificial viruses in tubulin-eGFP expressing HUH7 cells.

Main Results:

• Achieved 15 nm lateral and 50 nm axial spatial resolution.
• Reached a temporal resolution of 32 ms at moderate count rates.
• Successfully demonstrated tracking of artificial viruses within living cells.
• Generated particle trajectories suitable for super-resolution microtubule network analysis.

Conclusions:

• The developed orbital tracking microscope offers high-resolution, real-time 3D particle tracking.
• This method enables detailed investigation of particle-cell interactions.
• The system provides a powerful tool for super-resolution imaging of cellular structures like microtubules.