Nature 540, 588–592 (2016); doi:10.1038/nature20609

In Extended Data Fig. 4g of this Letter, the image showing the rabbit IgG control (top image) was incorrect. This image was mistakenly duplicated and cropped from the source image used in Extended Data Fig. 4f. A revised figure containing the corrected panels is now included as Supplementary Information to this Corrigendum. In addition, the Supplementary Information includes the raw microscope output images for Extended Data Fig. 4f and g. The error does not affect the results or conclusions of this Letter, and we apologize for any confusion this may have caused. The original Letter has not been corrected.