title: Direct measurement of the voltage sensitivity of second-harmonic generation from a membrane dye in patch-clamped cells.
abstract: We report what is to our knowledge the first optical imaging of voltage-clamped cells by second-harmonic generation. For the membrane-staining styryl dye di-4-ANEPPS, we determined the sensitivity of second-harmonic generation to be 18%/100 mV at an excitation wavelength of 850 ns. This sensitivity is significantly better than the optimal 10%/100 mV under fluorescence and further establishes the importance of second-harmonic generation for the functional imaging of membrane potential in living cells.
authors.affiliation: Center for Biomedical Imaging Technology, University of Connecticut Health Center, MC-1507, 263 Farmington Avenue, Farmington, Connecticut 06030-1507, USA. andrew.millard@physics.org
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Millard
authors.forename: Lei
authors.initials: L
authors.lastname: Jin
authors.forename: Aaron
authors.initials: A
authors.lastname: Lewis
authors.forename: Leslie M
authors.initials: LM
authors.lastname: Loew
mesh_terms: D000818:Animals; D005456:Fluorescent Dyes; D051379:Mice; D009447:Neuroblastoma / Q000503:physiopathology*; D018408:Patch-Clamp Techniques; D011726:Pyridinium Compounds; D014407:Tumor Cells, Cultured
chemical_list: D005456:Fluorescent Dyes; D011726:Pyridinium Compounds; C050019:1-(3-sulfonatopropyl)-4-(beta)(2-(di-n-butylamino)-6-naphthylvinyl)pyridinium betaine