Ultrafast imaging of cell elasticity with optical microelastography

TL;DR

This paper introduces a rapid optical microelastography technique that measures cell elasticity in live cells with high spatial and temporal resolution, overcoming limitations of existing methods.

Contribution

The authors developed a shear wave elastography method at the micrometer scale, enabling ultrafast, precise, and non-invasive elasticity mapping of live cells.

Findings

Elasticity of mouse oocytes decreases with cytoskeleton disruption

The technique achieves data acquisition in less than 1 ms

Spatial resolution of a few micrometers

Abstract

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 oocyte 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, robust, and thus represents a tractable novel option for interrogating biomechanical properties of diverse cell types.