SSPIM: a beam shaping toolbox for structured selective plane illumination microscopy.

Selective plane illumination microscopy (SPIM) represents a preferred method in dynamic tissue imaging, because it combines high spatiotemporal resolution with low phototoxicity. The OpenSPIM system was developed to provide an accessible and flexible microscope set-up for non-specialist users. Here, we report Structured SPIM (SSPIM), which offers an open-source, user-friendly and compact toolbox for beam shaping to be applied within the OpenSPIM platform. SSPIM is able to generate digital patterns for a wide range of illumination beams including static and spherical Gaussian beams, Bessel beams and Airy beams by controlling the pattern of a Spatial Light Modulator (SLM). In addition, SSPIM can produce patterns for structured illumination including incoherent and coherent array beams and tiling for all types of the supported beams. We describe the workflow of the toolbox and demonstrate its application by comparing experimental data with simulation results for a wide range of illumination beams. Finally, the capability of SSPIM is investigated by 3D imaging of Drosophila embryos using scanned Gaussian, Bessel and array beams. SSPIM provides an accessible toolbox to generate and optimize the desired beam patterns and helps adapting the OpenSPIM system towards a wider range of biological samples.