Principal Investigator Peter So
Project Website http://web.mit.edu/solab/Research/Microrheology.html
To shed lights on mechanotransduction pathways in cardiovascular cells, we wish to explore the relationships between cellular rheology and both the recruitment of signaling molecules and the cytoskeletal remodeling by the cell. To that end, we have designed and built a novel microrheological device, a fluorescence laser tracking microrheometer (FLTM), capable of determining the stress/strain relationship of a sample at specific intracellular locations.
This instrument expands upon the technology of laser tracking microrheometry developed to monitor the trajectory of a single fluorescent bead subjected to Brownian motion. Analysis based on the equipartition theorem subsequently allows for the extraction of the frequency-dependent complex shear modulus G*, index of the cell's resistance to deformation and fluid- vs. solid-like behavior.
The FLTM has a resolution of 5 nm over a frequency range extending from 1 Hz to 50 kHz. Additionally, our choice of fluorescent probes enables us to target cellular structures with molecular specificity.
We have demonstrated the capabilities of the FLTM by obtaining good agreement with previously reported rheological measurements of polyacrylamide gels. In vivo, the FLTM is also a valuable tool that enables the estimation of the fluid-like vs. solid-like properties of the cell cytoskeleton.