Enhanced contrast mechanisms for live cell structured illumination microscopy via fluorescence lifetime imaging

Super-resolved structured illumination microscopy (SR-SIM) is one of the most versatile and least perturbing fluorescence microscopy techniques capable of surpassing the optical diffraction limit and providing a high spatio-temporal resolution. However, the contrast mechanism was limited to the spectral domain so far. We developed a novel, ultra-compact interferometric SIM microscope providing multi-color, high-speed 2D-, TIRF- and 3D-SIM and compatible with short coherence length or picosecond laser sources. This system was combined with a custom electro-optic (EO) wide-field FLIM detector providing a high contrast, significant lower noise and cost-efficiency compared to established FLIM-cameras. This method provides both a high imaging speed and a large field of view (FOV). We applied the system on various samples including live-cells with a FOV of 60 µm and a spatial resolution of 130 nm. The lifetime accuracy with this system is 300 ps with a precision of 100 ps.