Photoactivatable fluorescent dye; supplied as an NHS ester for coupling to primary amine groups. Non-fluorescent until activated at 365 nm. Photochemical quantum yield of uncaging = 2.2%, with improved yield upon protein conjugation. Compatible with self-labeling tag systems (e.g. HaloTag? and SNAPtag?). Suitable for single molecule tracking and super resolution microscopy in live cells, specifically live cell sptPALM and fixed cell PALM. Can be multiplexed with PA Janelia Fluor? 646, SE (Cat. No. 6150) to perform two-color sptPALM in live cells with activation at 405 nm. Cell permeable. Excitation maximum = 551 - 553 nm; emission maximum = 570 - 573 nm. HaloTag is a trademark of Promega Corporation, and SNAP-tag is a trademark of New England BioLabs, Inc.. MW (observed): 575.58.