Biophysical Journal
Volume 103, Issue 1, 3 July 2012, Pages 11-18
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Article
Label-Free Imaging of Membrane Potential Using Membrane Electromotility

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Abstract

Electrical activity may cause observable changes in a cell's structure in the absence of exogenous reporter molecules. In this work, we report a low-coherence interferometric microscopy technique that can detect an optical signal correlated with the membrane potential changes in individual mammalian cells without exogenous labels. By measuring milliradian-scale phase shifts in the transmitted light, we can detect changes in the cells' membrane potential. We find that the observed optical signals are due to membrane electromotility, which causes the cells to deform in response to the membrane potential changes. We demonstrate wide-field imaging of the propagation of electrical stimuli in gap-junction-coupled cell networks. Membrane electromotility-induced cell deformation may be useful as a reporter of electrical activity.

Cited by (0)

Michael S. Feld is deceased.

Seungeun Oh's present address is Department of Systems Biology, Harvard University, Boston, MA.

Wonshik Choi's present address is Department of Physics, Korea University, Seoul, Korea.

Dan Fu's present address is Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA.

Christopher Fang-Yen's present address is Department of Bioengineering, University of Pennsylvania, Philadelphia, PA.

YongKeun Park's present address is Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, Korea.