Biophysics Journal Club

Ultrafast imaging of cell elasticity with optical microelastography

Mon, 25 Jun 2018 12:30 PM
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Biophysics Journal Club

Ultrafast imaging of cell elasticity with optical microelastography

Steven Large
P. Grasland-Mongrain, A. Zorgani, et al., PNAS. 115 (5) 861-866 (2018)

June 25, 2018 at 12:30pm in P8445.2

Synopsis

Elasticity is a fundamental cellular property that is related to the anatomy, functionality, and pathological state of cells and tissues. However, current techniques based on cell deformation, atomic force microscopy, or Brillouin scattering are rather slow and do not always accurately represent cell elasticity. Here, we have developed an alternative technique by applying shear wave elastography to the micrometer scale. Elastic waves were mechanically induced in live mammalian oocytes using a vibrating micropipette. These audible frequency waves were observed optically at 200,000 frames per second and tracked with an optical flow algorithm. Whole-cell elasticity was then mapped using an elastography method inspired by the seismology field. Using this approach we show that the elasticity of mouse oocytes is decreased when the oocyte cytoskeleton is disrupted with cytochalasin B. The technique is fast (less than 1 ms for data acquisition), precise (spatial resolution of a few micrometers), able to map internal cell structures, and robust and thus represents a tractable option for interrogating biomechanical properties of diverse cell types.