Light-sheet fluorescence microscopy (LSFM) illuminates the sample with an “excitation light sheet” that is conjugate to the focal plane, and achieves three-dimensional imaging by axially scanning the sample layer by layer and acquiring two-dimensional images. Because the excitation light is confined to a thin sheet near the detection focal plane, LSFM offers excellent three-dimensional spatial resolution, strong optical sectioning capability, high imaging speed, and extremely low photobleaching, making it well suited for three-dimensional imaging of a wide range of biological specimens.

　　The thickness of the excitation light sheet, the light sheet’s ability to confine the excitation light, and its size collectively determine the three-dimensional resolution, optical sectioning capability, and imaging field of view of LSFM. Consequently, enhancing LSFM performance hinges on generating a thin, uniform excitation light sheet that spans the entire imaging field while confining the excitation light as tightly as possible to the focal plane. However, due to diffraction, no single light sheet can optimally satisfy all these requirements; thus, when using LSFM for three-dimensional imaging of biological samples, one must strike a balance among spatial resolution, optical sectioning quality, and imaging field of view, tailored to the specific research objectives.

　　The Nuohai LS18 light-sheet microscope, by employing a real-time adjustable light sheet, not only overcomes the limitations of conventional light-sheet microscopy in various performance aspects but also enables an optimal trade-off among three-dimensional spatial resolution, optical sectioning capability, and imaging field of view, tailored to the characteristics of the sample and specific imaging requirements. This flexibility allows the microscope to be readily adapted to a wide range of applications. Compared with other light-sheet microscopes, the LS18 offers several advanced features:

　　Sample illumination is achieved using a dynamic virtual‑plane light sheet, which enhances three-dimensional spatial resolution, tomographic capability, and imaging throughput while preserving the imaging field of view.

　　The numerical aperture, imaging magnification, the size of the excitation light sheet, and the number of tiling steps can all be easily adjusted, enabling the microscope to image centimeter-scale cleared samples with spatial resolution ranging from the micrometer to the sub‑micrometer scale. When combined with tissue expansion techniques, this resolution can be further improved to the hundred‑nanometer level (~70 nm).

　　It enables real-time preview and optimization of the tiled light sheet used for sample illumination, and employs an automatic calibration function to correct various alignment errors in the excitation light sheet, thereby ensuring imaging accuracy, reliability, and ease of use.

　　LS18 is compatible with a variety of clearing methods and is suitable for three-dimensional imaging of biological tissues with diverse shapes and mechanical properties.

　　Nuohai LS18 Plan-Achromatic Objective Microscope

　　Ongoing advances in tissue‑clearing technologies have made it possible to clear and perform three-dimensional imaging of larger biological specimens, such as whole mice. This has, in turn, generated strong demand for ultra‑widefield, high‑speed imaging capabilities, which the latest upgrade of the NOVA LS18 now fulfills.

　　Taking the imaging of an entire adult mouse brain as an example, the LS18 can complete three-dimensional imaging of the whole brain at a spatial resolution of approximately 10–20 micrometers in just 10 seconds, while simultaneously performing 3D reconstruction and visualization of the acquired data. Although the resulting 3D spatial resolution is relatively low, we can still clearly visualize the three-dimensional architecture of the target tissue, enabling us to determine whether higher‑resolution 3D imaging of the sample is required. This capability not only meets users’ need for rapid preliminary screening prior to high‑resolution 3D imaging of large‑volume samples, but also effectively supports high‑throughput, relatively lower‑resolution 3D imaging of centimeter‑scale specimens.

　　Nuohai Life Sciences is committed to providing life science researchers with superior, user-friendly imaging tools and technologies. Nuohai will continue to refine and optimize its product performance based on customer feedback, ensuring that it meets the diverse needs of our users.

　　References

　　Gao L. Optimization of the excitation light sheet in selective plane illumination microscopy. Biomed Opt Express. 2015;6(3):881-890.

　　Chen Y, Li X, Zhang D, et al. A Versatile Tiling Light Sheet Microscope for Imaging of Cleared Tissues. Cell Rep. 2020;33(5):108349.

　　Hobson CM,Guo M,Vishwasrao HD,Wu Y,Shroff H,Chew TL.Practical considerations for quantitative light sheet fluorescence microscopy.Nat Methods.2022;19(12):1538-1549.