STED reveals the super-resolution localization of known Golgi and vesicular markers. (A–H) HeLa cells were immunostained with antibodies against the Golgi markers indicated in the figure and secondaries labeled with either ATTO647N or AlexaFluor594 to be able to perform dual-color STED experiments. Line profiles in each panel correspond to the dotted boxes in the cropped images. (B) Yellow arrows highlight fenestrations in the Golgi cisterna, while white arrows highlight COPI-positive vesicular structures. (E) White arrow highlights a Golgi-associated ERGIC structure. (I) Graphical summary of the nanoscale localization of Golgi markers. All images were deconvolved, background subtracted, and smoothed with a Gaussian filter as described in Materials and methods. Scale bars are 5 and 1 µm in the cropped images.