Confocal interferometric scattering microscopy reveals 3D nanoscopic structure and dynamics in live cells

Area of Science:

• Biophysics
• Cell Biology
• Microscopy

Background:

• Light microscopy provides label-free biological insights but lacks 3D imaging and sensitivity to nanoscopic features.
• Existing techniques struggle with high-end quantitative studies on live cells due to limitations in resolution and sensitivity.

Purpose of the Study:

• To demonstrate confocal interferometric scattering (iSCAT) microscopy as a label-free solution for live-cell studies.
• To reveal nanoscale topography, quantify cellular dynamics, and track nanoscopic entities in real-time.

Main Methods:

• Utilized confocal interferometric scattering (iSCAT) microscopy for high-resolution, label-free imaging of live cells.
• Combined confocal and wide-field iSCAT for simultaneous imaging and high-speed tracking of nanoscopic entities.
• Benchmarked iSCAT findings against simultaneously acquired fluorescence images.

Main Results:

• Revealed nanometric topography of the nuclear envelope and quantified endoplasmic reticulum dynamics.
• Successfully detected single microtubules and mapped nanoscopic diffusion of clathrin-coated pits.
• Demonstrated high-speed tracking of single SARS-CoV-2 virions using combined iSCAT modalities.

Conclusions:

• Confocal iSCAT microscopy provides unique label-free solutions for live-cell studies, overcoming limitations of traditional methods.
• The technique is readily implementable in existing laser scanning microscopes, enhancing their capabilities.
• Ideal for studying primary cells and long-duration experiments where photobleaching is a concern.