Acoustic light-sheet microscopy

Light-sheet imaging with tissue clearing methods is an indispensable tool for mapping whole biological systems with single-cell resolution. However, there is a trade-off between field-of-view and axial resolution originating from the diffraction of the light, which remains an open challenge to achieve wide-field high resolution images of large organs. The newly developed acoustic light-sheet microscopy (ALSM) actively manipulates the light propagation inside a large sample to obtain wide-field microscopic images deep inside a target with high axial resolution. By accurately coupling a light-sheet illumination pulse into a planar acoustic pulse, the light-sheet is continuously refocused over large distances.

This work gives an introduction to light-sheet fluorescence microscopy in brain imaging, explores the principles of acoustic-optical guiding and presents a way how these two concepts can be in-cooperated with each other. Planar acoustic pulses in biological tissues were visualized by Schlieren imaging to reveal their shape and propagation. Additionally, an acoustic-optical simulation framework was established to gain a fundamental understanding of the complex interaction of sound and light. As proof-of-concept, ALSM was used to image a fluorescence-labeled transparent mouse brain with field-of-views of 19.3 x 12.4 mm^2 and 9.7 x 5.9 mm^2, with resolved microstructures and single cells deep inside the brain. ALSM is an unique acoustic-optical approach to reduce the light-sheet thickness and increase axial resolution up to 3-fold compared to a conventional gaussian light-sheet, creating new opportunities for the application of light-sheets in the field of industry to basic science.