title: Real-time monitoring of changes in plasma membrane potential via imaging of fluorescence resonance energy transfer at individual cell resolution in suspension.
abstract: A method for monitoring heterogeneity in changes of plasma membrane potential (PMP) at an individual cell resolution while in suspension, utilizing a simple and low-cost wide-field illumination arrangement, is presented. The method is modeled via HEK-293 cell line in suspension, double stained with coumarin and oxonol (donor and acceptor), which were loaded into an array of nanoliter wells, each designed to preserve the individuality of the nontethered cell it holds during vigorous biomanipulation. Depolarization of PMP was induced by high K(+) solution, reducing the proximity between the membrane fluorophores and subsequently reducing the efficiency (E%) of resonance energy transfer between them. Spatial plots of E% were produced from both images of fluorescence intensity and polarization. The spatial resolution of E% plots seem to be higher, and their contrast greater, when calculated from the polarization, rather than from the intensity of the fluorescence.
authors.affiliation: Bar Ilan University, The Biophysical Interdisciplinary Schottenstein Center for the Research and the Technology of the Cellome, Department of Physics, Ramat Gan, Israel.
authors.forename: Tzachi
authors.initials: T
authors.lastname: Sabati
authors.affiliation: Bar Ilan University, The Biophysical Interdisciplinary Schottenstein Center for the Research and the Technology of the Cellome, Department of Physics, Ramat Gan, Israel.
authors.forename: Bat-Sheva
authors.initials: BS
authors.lastname: Galmidi
authors.affiliation: Bar Ilan University, The Mina and Everard Goodman Faculty of Life Sciences, Ramat Gan, Israel.
authors.forename: Alon
authors.initials: A
authors.lastname: Korngreen
authors.affiliation: Bar Ilan University, The Biophysical Interdisciplinary Schottenstein Center for the Research and the Technology of the Cellome, Department of Physics, Ramat Gan, Israel.
authors.forename: Naomi
authors.initials: N
authors.lastname: Zurgil
authors.affiliation: Bar Ilan University, The Biophysical Interdisciplinary Schottenstein Center for the Research and the Technology of the Cellome, Department of Physics, Ramat Gan, Israel.
authors.forename: Mordechai
authors.initials: M
authors.lastname: Deutsch
mesh_terms: D002462:Cell Membrane / Q000737:chemistry* / Q000502:physiology*; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D057809:HEK293 Cells; D006801:Humans; D008564:Membrane Potentials / Q000502:physiology*; D059010:Single-Cell Analysis / Q000379:methods*