title: Synthesis of a Far-Red Photoactivatable Silicon-Containing Rhodamine for Super-Resolution Microscopy.
abstract: The rhodamine system is a flexible framework for building small-molecule fluorescent probes. Changing N-substitution patterns and replacing the xanthene oxygen with a dimethylsilicon moiety can shift the absorption and fluorescence emission maxima of rhodamine dyes to longer wavelengths. Acylation of the rhodamine nitrogen atoms forces the molecule to adopt a nonfluorescent lactone form, providing a convenient method to make fluorogenic compounds. Herein, we take advantage of all of these structural manipulations and describe a novel photoactivatable fluorophore based on a Si-containing analogue of Q-rhodamine. This probe is the first example of a "caged" Si-rhodamine, exhibits higher photon counts compared to established localization microscopy dyes, and is sufficiently red-shifted to allow multicolor imaging. The dye is a useful label for super-resolution imaging and constitutes a new scaffold for far-red fluorogenic molecules.
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA, 20147, USA.
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Grimm
authors.affiliation: Department of Biotechnology and Biophysics, Julius Maximilian University Wuerzburg, Am Hubland, 97074, Wuerzburg, Germany.
authors.forename: Teresa
authors.initials: T
authors.lastname: Klein
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA, 20147, USA.|Hope College, Department of Biology, 35 E. 12th Street, Holland, MI, 49423, USA.
authors.forename: Benjamin G
authors.initials: BG
authors.lastname: Kopek
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA, 20147, USA.
authors.forename: Gleb
authors.initials: G
authors.lastname: Shtengel
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA, 20147, USA.
authors.forename: Harald F
authors.initials: HF
authors.lastname: Hess
authors.affiliation: Department of Biotechnology and Biophysics, Julius Maximilian University Wuerzburg, Am Hubland, 97074, Wuerzburg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Sauer
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA, 20147, USA. lavisl@janelia.hhmi.org.
authors.forename: Luke D
authors.identifier: http://orcid.org/0000-0002-0789-6343
authors.initials: LD
authors.lastname: Lavis
mesh_terms: D008856:Microscopy, Fluorescence / Q000379:methods*; D012235:Rhodamines / Q000737:chemistry*; D012825:Silicon / Q000032:analysis*
chemical_list: D012235:Rhodamines; D012825:Silicon
keywords: Si-rhodamine; fluorophore; microscopy; photoactivation; super-resolution imaging