title: Ultra-bright and -stable red and near-infrared squaraine fluorophores for in vivo two-photon imaging.
abstract: Fluorescent dyes that are bright, stable, small, and biocompatible are needed for high-sensitivity two-photon imaging, but the combination of these traits has been elusive. We identified a class of squaraine derivatives with large two-photon action cross-sections (up to 10,000 GM) at near-infrared wavelengths critical for in vivo imaging. We demonstrate the biocompatibility and stability of a red-emitting squaraine-rotaxane (SeTau-647) by imaging dye-filled neurons in vivo over 5 days, and utility for sensitive subcellular imaging by synthesizing a specific peptide-conjugate label for the synaptic protein PSD-95.
authors.affiliation: Department of Cellular and Physiological Sciences and Brain Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Kaspar
authors.initials: K
authors.lastname: Podgorski
authors.forename: Ewald
authors.initials: E
authors.lastname: Terpetschnig
authors.forename: Oleksii P
authors.initials: OP
authors.lastname: Klochko
authors.forename: Olena M
authors.initials: OM
authors.lastname: Obukhova
authors.forename: Kurt
authors.initials: K
authors.lastname: Haas
mesh_terms: D000818:Animals; D003503:Cyclobutanes / Q000737:chemistry* / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry* / Q000378:metabolism; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism; D009474:Neurons / Q000737:chemistry / Q000378:metabolism; D010636:Phenols / Q000737:chemistry* / Q000378:metabolism; D017785:Photons; D043862:Rotaxanes / Q000737:chemistry / Q000378:metabolism; D000074407:SAP90-PSD95 Associated Proteins; D013569:Synapses / Q000737:chemistry / Q000378:metabolism; D014982:Xenopus laevis
chemical_list: D003503:Cyclobutanes; D005456:Fluorescent Dyes; D009419:Nerve Tissue Proteins; D010636:Phenols; D043862:Rotaxanes; D000074407:SAP90-PSD95 Associated Proteins; C480596:squaraine