Expanding super-resolution imaging versatility in organisms with multi-confocal image scanning microscopy.

Area of Science:

• Biophysics
• Cell Biology
• Microscopy

Background:

• Live tissue imaging requires balancing resolution, field-of-view, and phototoxicity.
• Confocal laser scanning microscopy advancements like image scanning microscopy (ISM) improve resolution but face speed limitations for in vivo applications.

Purpose of the Study:

• To develop a multi-confocal image scanning microscopy (MC-ISM) technique that overcomes the spatiotemporal resolution and speed limitations of current live tissue imaging methods.
• To enable high-speed, high-resolution, non-invasive 3D imaging of subcellular dynamics in live biological tissues.

Main Methods:

• Optimized pinhole diameter and pitch to eliminate out-of-focus signals.
• Implemented a frame reduction reconstruction algorithm to increase imaging speed by 16 times compared to multifocal structured illumination microscopy.
• Utilized a single-galvo scan mechanism for high-speed, high-accuracy scanning.

Main Results:

• Achieved a 16-fold increase in imaging speed.
• Enabled continuous imaging of mitochondria dynamics in live cells for 1000 frames with no apparent phototoxicity.
• Reached an imaging depth of 175 μm.
• Successfully visualized the inner membrane structure of living mitochondria in Arabidopsis hypocotyl for the first time.

Conclusions:

• MC-ISM significantly enhances spatiotemporal resolution and imaging speed for live tissue microscopy.
• The technique offers high photon efficiency, allowing deep tissue imaging with minimal phototoxicity.
• MC-ISM represents a breakthrough for observing dynamic subcellular structures in vivo.