As a fluorescence imaging technique, it utilizes a planar sheet of light in order to illuminate the live sample and excite fluorophores within a specific focal volume. The excitation light can either be created using a cylindrical lens or virtually generated using a scanning beam or dithering beam array.

The latter technique is normally referred to as digitally scanned laser light sheet microscopy (DSLM), while the former is called selective plane illumination microscopy, or SPIM.

Detection occurs along an axis perpendicular to that of illumination so that only the section being observed is lit, rather than the entire specimen or any out-of-focus features. This planar illumination technique produces optical sectioning, or clear images of multiple focal planes within the sample.

Furthermore, using the perpendicular axis reduces the amount of photo-damage, photo-bleaching, and phototoxicity to the specimen so that imaging can occur long-term.

It makes light sheet microscopy more ideal compared to processes like wide-field fluorescence microscopy that can damage your sample more rapidly and reduce long-term viability.

Optical sectioning offers a wide field of view, increased contrast, faster image acquisition speeds, and high axial resolution and spatial resolution. These capabilities support a variety of applications, including the real-time, three-dimensional imaging monitoring of neural responses in live organisms, and enable the 3D reconstruction of a 2D image by computationally combining the image data from a stack of images.

Light sheet microscopy’s principle benefits apply across multiple fields, including drug discovery, neurobiology, developmental biology, embryology, plant biology, and more.

Being able to 3D image everything from large, live organisms, tissue explants, to 3D cell cultures and single cells is crucial in many different areas of research.

This is especially true in developmental biology, where many model organisms are used to understand human development, such as fruit fly embryos (Drosophila melanogaster), an excellent model system for understanding the basic biology underlying our own embryonic development.

Another example of these organisms is the zebrafish, which is primarily used to study vascular development and disease.

Light sheet imaging has been pivotal in 3D examination, avoiding disruption or damage of the organism’s development cycle.