Large-scale expanded sample imaging with tiling lattice lightsheet microscopy

The ability to observe biological nanostructures forms a vital step in understanding their functions. Thanks to the invention of expansion microscopy (ExM) technology, super-resolution features of biological samples can now be easily visualized with conventional light microscopies. However, when the sample is physically expanded, the demand for deep and precise 3D imaging increases. Lattice lightsheet microscopy (LLSM), which utilizes a planar illumination that is confined within the imaging depth of high numerical aperture (NA=1.1) detection objective, fulfils such requirements. In addition, optical tiling could be implemented to increase the field of view (FoV) by moving the lightsheet without mechanically moving the samples or the objective for high-precision 3D imaging. In this review article, we will explain the principle of the tiling lattice lightsheet microscopy (tLLSM), which combines optical tiling and lattice lightsheet, and discuss the applications of tLLSM in ExM. •A deep and precise 3D microscopic method is required when imaging expanded or large-volume samples.•Lightsheet microscopy is an excellent tool to image thick samples with a high 3D resolution and minimal photobleaching.•Longer lightsheet leads to lower axial resolution, therefore shorter lightsheets are used to tile over the large sample.•Tiling could be achieved by mechanically moving the sample, but the subsequent image processing is tedious.•The tLLSM is introduced to optically tile the lightsheet within the sample with minimal sample movement.