Axially Swept Light-Sheet Microscopy using scattering and fluorescence contrast mechanisms.

Light-sheet fluorescence microscopy (LSFM) has found numerous applications in the life sciences through its gentle, rapid and efficient volumetric imaging capabilities. It would be advantageous if its rapid 3D imaging capabilities could be extended to non-fluorescent contrast mechanisms such as light-scattering. Yet, the coherent illumination with a light-sheet can cause cross-interference from multiple scatterers. Consequently, this can lead to an object-variant point-spread function, which complicates image analysis. Here we show that by combining axially swept illumination with sparse, but strong scatterers can lead to 3D imaging of comparable quality to traditional fluorescent light-sheet microscopy. We leverage axial sweeping of a light-sheet to both record fluorescence and scattered signals in expanded breast cancer spheroids seeded with gold nanoparticles.