Switching of Organic Fluorophores by Glycerol‐sulfite Interactions for Single‐Molecule Super‐Resolution Microscopy**

Photoinduced off-switching of organic fluorophores is used in super-resolution microscopy to separate and localize single fluorescent molecules. However, this method typically relies on the use complex imaging buffers that make enzymatic oxygen scavengers remove primary thiols reversibly reduce excited a non-fluorescent state. Here, we show interactions between sodium sulfite glycerol can also be for efficient switching common fluorophores. The addition buffer allows us tune dye from intermittent fluorescence off-state. We additionally sulfite-glycerol-based are especially useful at low laser illumination intensities high-refractive index solutions samples embedded agarose gel. This significantly simplifies implementation different modalities such as direct STochastic Optical Reconstruction Microscopy (dSTORM) Super-resolution Fluctuation Imaging (SOFI).