UCLA

Light-sheet fluorescence microscopy stands out in the field of bioimaging as its rapid imaging speed, deep penetration depth, and reduced phototoxicity and photobleaching. However, an essential step in imaging large tissues is optical clearing. This process removes lipids, pigments, and calcium phosphate, which are not conducive to clear imaging, and matches the specimen's refractive index with the imaging medium to achieve high transparency. Numerous optical clearing strategies are employed, categorized into three main types: hydrophobic, hydrophilic, and hydrogel-based, each with distinct refractive indices. Typically, biologists design an optical system tailored to a specific sample and clearing method, restricting it to one fixed refractive index.

This thesis hereby proposes a light-sheet system compatible with various tissue clearing methods with large field of view. The system also integrates multi-view reconstruction algorithm to maintain stable high resolution. Its performance is assessed by measuring the point spread function and imaging different specimens: Tg(flk1:mcherry) zebrafish in water, mouse retina cleared by CLARITY, αMHCCre; R26VT2/GK mouse rainbow heart cleared by CUBIC, and mouse descending aorta cleared by iDISCO+. The system demonstrated robustness across multiple optical clearing approaches while maintaining high resolution and a large field of view. It offers the possibility for biologists to explore diverse tissue clearing strategies and study various tissues using a single system.