Accession Number : ADA328780

Title :   The Optical Patch Clamp Stage II: Non-Linear Optics as a Probe of Membrane Potential in Living Cells.

Descriptive Note : Final rept. 1 Jan 95-30 Jun 97,

Corporate Author : CONNECTICUT UNIV HEALTH CENTER FARMINGTON

Personal Author(s) : Loew, Leslie M.

PDF Url : ADA328780

Report Date : 05 AUG 1997

Pagination or Media Count : 41

Abstract : A series of new dyes with superior binding and second harmonic generation (SHG) efficiencies have been synthesized. These dyes are all based on the aminonapthyl-ethenyl-pyridinium chromophore used in our earlier studies of fluorescent potentiometric dyes. We have calibrated the potential-dependent response of the SHG signal on a model membrane system and found the response to be several times more sensitive than the fluorescence signal used most commonly for voltage-sensitive dyes. The utility of the SHG signal for following the membrane potential changes in a system of excitable cells, the visual system of the housefly Musca domestica has been established. This is a particularly appropriate application of the method since the infrared probing light is not absorbed by the photoreceptor cells. A significant enhancement of the SHG signal when the dyes are absorbed to colloidal silver has been demonstrated, suggesting that this approach might be applied to probing the electrical activity of single molecules on a cell surface. Finally, we have obtained the first SHG microscopic images, demonstrating the utility of SHG as a new modality for non- destructive selective contrast in 3D microscopy of living cells.

Descriptors :   *OPTICS, *MEMBRANES, *DYES, *CELLS(BIOLOGY), REPRINTS, PROBES, CHROMOPHORES, MOLECULES, EXCITATION, HIGH RESOLUTION, MICROSCOPY, NONLINEAR SYSTEMS, IMAGES, FLUORESCENT DYES, ELECTROPHYSIOLOGY, PHOTORECEPTORS, BIOLOGICAL STAINS.

Subject Categories : Anatomy and Physiology
      Coatings, Colorants and Finishes
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE