Cristina Martínez Torres
| When |
Sep 25, 2015
from 02:00 to 04:25 |
|---|---|
| Where | Salle des thèses, site Monod, ENS de Lyon |
| Contact Phone | (33) 04 72 72 88 49 |
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Abstract:
A living cell undergoes a series of active and passive processes occurring in a wide range of temporal scales. From the dynamics of single macromolecules (micro to milliseconds) and up to the cell cycle (hours), the cell performs a temporal integration of all its internal processes. One example that illustrates this interplay across the spatio-temporal scales, is mechanotransduction, that is, how the cell translates the mechanical properties of its environment into biochemical signals. Since the mechanical properties of a cell confer to it the ability to respond temporally and spatially to its environment, we consider here the cell mechanics as an essential factor to explain their regulation and modification in pathological situations. We have developed a methodology that allows to cover a broad frequency spectrum based on two techniques suited to study single-cell mechanics: Diffraction Phase Microscopy (DPM) and Atomic Force Microscopy (AFM). DPM is a non-intrusive optical technique that quantifies the optical phase of the object, proportional to the product of its refractive index and thickness. We complement DPM, that covers a range of frequency from the microHz to kHz, with AFM, that offers a greater spatial resolution with a frequency range from mHz to MHz, allowing also to evaluate the cell response to a local mechanical perturbation.