Surpassing the optical diffraction limit by matrix structured illumination microscopy with patterned excitation and patterned stimulated emission depletion

The resolution of traditional fluorescence microscopy is limited due to the optical diffraction. Various techniques have been developed to surpass the diffraction limit in recent years. Among these methods, nonlinear structured illumination microscopy (nonlinear SIM) is able to provide fast imaging speed, wide field of view and considerable resolution enhancement simultaneously. However, the current developed nonlinear SIM approaches have their own defects. We report a potential better nonlinear SIM for live-cell imaging termed ‘Matrix STED-SIM’ with patterned illumination based on both structured excitation grid and stimulated emission depletion (STED) grid. Theory and simulation analysis are presented for illustrating the feasibility of our method to achieve better super-resolution imaging than other current approaches. In addition, we demonstrate the robustness and potential practicability of this new method considering the impact of image noise and exposures.