Direct measurement of the voltage sensitivity of second-harmonic generation from a membrane dye in patch-clamped cells

Opt Lett. 2003 Jul 15;28(14):1221-3. doi: 10.1364/ol.28.001221.


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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Fluorescent Dyes
  • Mice
  • Neuroblastoma / physiopathology*
  • Patch-Clamp Techniques
  • Pyridinium Compounds
  • Tumor Cells, Cultured


  • Fluorescent Dyes
  • Pyridinium Compounds
  • 1-(3-sulfonatopropyl)-4-(beta)(2-(di-n-butylamino)-6-naphthylvinyl)pyridinium betaine