Label-free subcellular imaging with dynamic spectrally encoded confocal microscopy (D-SECM) with subpixel jitter...

Area of Science:

• Biomedical Optics
• Microscopy
• Cellular Metabolism

Background:

• Label-free imaging is crucial for real-time biological process visualization.
• Current high-speed microscopy techniques often require exogenous labels, limiting applications.
• Subcellular metabolic activity is a key indicator of cell function and disease.

Purpose of the Study:

• To introduce dynamic spectrally encoded confocal microscopy (D-SECM) as a novel high-speed, label-free imaging modality.
• To demonstrate the capability of D-SECM for real-time visualization of subcellular metabolic activity.
• To validate D-SECM's performance in various biological tissues and organs.

Main Methods:

• Developed a modified swept source SECM system synchronized by fiber-Bragg grating.
• Implemented real-time pixelwise power spectra mapping into frequency-dependent RGB channels using GPU acceleration.
• Acquired sequential, optically sectioned SECM images at 100 fps with 0.62–0.88 µm lateral resolution.

Main Results:

• Demonstrated label-free visualization of metabolic contrast in mouse liver tissue with exposure as short as 40 ms.
• Achieved 3D D-SECM image acquisition within one second using volume-prioritized scanning.
• Successfully applied D-SECM to multiple organs, including liver, lung, thyroid, kidney, and pancreas.

Conclusions:

• D-SECM is a powerful and scalable platform for high-speed, label-free imaging of metabolic dynamics.
• The technique enables real-time visualization of subcellular metabolic activity.
• D-SECM holds significant potential for both basic research and clinical applications.