Petar Petrov
Postdoctoral Scholar at University of California, Berkeley
Date and time: March 1st, 2023
Wednesday, at 8am PST / 11am EST / 4pm GMT / 5pm CET / midnight China
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Laser phase-contrast Cryo-EM and associated computational opportunities
A phase plate can provide optimum image contrast for weak-phase objects in transmission electron microscopy, but approaches toward realizing a phase plate have suffered from instabilities. We have developed a phase plate that is based on coherently phase-shifting the electron wave function by a laser beam, which is built up to a record-high intensity of ~400 GW/cm^2 by resonance in a Fabry-Perot cavity. We have demonstrated contrast enhancement with the laser phase plate (LPP) and shown the long-term stability of the device, as well as generated a high-resolution map of 20S proteasome particles using a standard single-particle cryo-electron microscopy (Cryo-EM) workflow.
This talk will focus on our recent work to move beyond proof-of-concept, as well as the computational opportunities that lie ahead. To demonstrate the benefits of the LPP to Cryo-EM as well as cryo-electron tomography, we will soon begin working with a state-of-the-art microscope equipped with a spherical aberration corrector, gun monochromator, and post column energy filter. We will explore improvements to the phase plate design and pursue new strategies for image acquisition and processing, such as high-resolution two-dimensional template matching.