HM Janelia Fluor 526, SE (HM-JF526 NHS) is a derivative of hydroxymethyl JF526 (HM-JF526). SMLM (single-molecule localization microscopy) imaging in standard phosphate-buffered saline (pH 7.4) revealed that the HM-JF526 label showed spontaneous blinking behavior throughout the imaging session and did not require short-wavelength activation light.