Lateral resolution gain. Estimating the resolution gain in the x-y-plane. A) Fluorescence image. B) SOFI image. The boxed regions are displayed magnified and intensity-normalized in C) and E). Blue and red lines indicate where the cross-section was taken in order to evaluate the resolution gain. D): intensity profiles along the lines of C) and E). Blue line: Cross-section of the original fluorescence image. Red line: Cross-section of the SOFI image. As can be seen the blue line displays a dip indicating a higher resolution. The distance between the vertical black lines amounts to 215 nm, which is 14% higher than the theoretically expected resolution of 188 nm. Scalebar in A) and B) 20 μm; C) and E) 1 μm.