A fully water coupled oblique light-sheet microscope.

Recently developed descanned versions of the oblique light-sheet microscope promise to enable high-frame rate volumetric imaging in a variety of convenient preparations. The efficiency of these microscopes depends on the implementation of the objective coupling that turns the intermediate imaging plane. In this work, we developed a fully immersed coupling strategy between the middle and end objectives of the oblique light-sheet microscope to enable facile alignment and high efficiency coupling. Our design outperformed conventional designs that used only air objectives in resolution and light-collection power. We further demonstrated our design's ability to capture large fields-of-view when paired with a camera with built-in electronic binning. We simultaneously imaged the forebrain and hindbrain of larval zebrafish and found clusters of activity localized to each region of the brain.