Cell quake elastography

The ability to measure the elasticity of a cell provides information about its anatomy, function, and pathological state. Many techniques have been proposed to measure mechanical properties of single cells but most need a model of the cell characteristics and the fixation of the cell on a substrate. Moreover, current measurements take seconds to hours to perform, during which biological processes can modify the 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 actuator. These audible frequency waves were observed optically at 205,000 frames per second and tracked with an optical flow algorithm previously developed in the context of ultrasound elastography. Whole-cell elasticity was then reconstructed using an elastography method inspired by the seismology field. Using this approach we showed that the elasticity of mouse oocytes is decreased when t...