Two-photon excitation improves multifocal structured illumination microscopy in thick scattering tissue

Area of Science:

• Biomedical Optics
• Microscopy Techniques
• Cell Biology

Background:

• Multifocal structured illumination microscopy (MSIM) offers resolution beyond the diffraction limit.
• Scattered light in thick samples limits MSIM performance.
• Efficient excitation is crucial for deep-tissue imaging.

Purpose of the Study:

• To enhance Multifocal structured illumination microscopy (MSIM) performance in thick, scattering samples.
• To enable efficient two-photon excitation within MSIM.
• To improve image quality, sectioning, and contrast for deep-tissue biological imaging.

Main Methods:

• Implementation of MSIM combined with a microlens array.
• Utilizing two-photon excitation for enhanced optical sectioning.
• Imaging of various thick biological specimens including C. elegans embryos, Drosophila salivary glands, and mouse liver tissue.

Main Results:

• Achieved twofold resolution enhancement beyond the diffraction limit.
• Demonstrated improved sectioning and contrast in thick scattering samples.
• Successfully imaged complex biological structures with enhanced clarity.

Conclusions:

• Two-photon MSIM provides superior imaging in challenging biological samples.
• This technique significantly overcomes the limitations of conventional MSIM in scattering tissues.
• The developed method offers a valuable tool for deep-tissue biological research.