Long-wavelength oblique back-illumination microscopy for deep in vivo imaging

Area of Science:

• Biomedical optics
• Microscopy
• In vivo imaging

Background:

• Oblique back-illumination microscopy (OBM) is a label-free imaging method.
• OBM generates high-contrast images by detecting forward-scattered light in reflection mode.
• Tissue scattering limits OBM's imaging depth in biological tissues.

Purpose of the Study:

• To extend the imaging depth of OBM.
• To mitigate scattering effects in biological tissues.
• To develop a long-wavelength OBM system for deeper in vivo imaging.

Main Methods:

• Implemented a novel OBM system operating at 1650 nm wavelength.
• Compared the 1650 nm OBM system with an 800 nm system for in vivo mouse brain imaging.
• Evaluated imaging depth and contrast in biological tissues.

Main Results:

• The 1650 nm OBM system achieved significantly deeper in vivo imaging of the mouse brain compared to the 800 nm system.
• Longer wavelengths effectively mitigated scattering effects, enabling deeper penetration.
• High-contrast pseudo-transmission images were obtained at extended depths.

Conclusions:

• Long-wavelength OBM (1650 nm) significantly enhances imaging depth in scattering biological tissues.
• This advancement facilitates deeper in vivo investigations of the mouse brain.
• The developed OBM system offers potential for detailed studies in living biological systems and their pathophysiology.