High-resolution dynamic full-field optical coherence microscopy: illuminating intracellular activity in deep tissue.

Area of Science:

• Biomedical Optics
• Microscopy
• Label-free Imaging

Background:

• Dynamic full-field optical coherence microscopy (d-FF-OCM) offers label-free, functional contrast based on subcellular motion.
• Current d-FF-OCM faces challenges with deep-tissue penetration and high-resolution imaging in scattering samples.

Purpose of the Study:

• To develop and present a novel high-resolution d-FF-OCM system.
• To enable depth-extended, high-resolution imaging in highly scattering biological tissues.

Main Methods:

• Utilized 100× oil-immersion objectives (NA=1.25) and a high-brightness, laser-pumped incoherent white light source.
• Implemented real-time reference arm adjustment for consistent signal and contrast at depth.
• Achieved nanometre-scale resolution at depths up to ~120 µm in scattering samples.

Main Results:

• Demonstrated depth-extended, high-resolution imaging capabilities in challenging biological samples.
• Successfully imaged fresh ex vivo mouse liver and small intestine with unprecedented detail.
• Revealed fine structures like sinusoidal microvasculature, organized cell layers, neural plexuses, and crypts label-free.

Conclusions:

• The new d-FF-OCM system overcomes limitations of previous implementations for deep-tissue imaging.
• This technology provides label-free visualization of intricate subcellular and tissue structures.
• Offers a powerful tool for studying tissue morphology and function in vivo.