Seminar by Paul Ashby

Toward Imaging Membrane Protein Assembly and Dynamics with In-situ Atomic Force Microscopy

Paul Ashby, Ph.D.

Lawrence Berkeley National Laboratory

Abstract

Membrane protein clustering is important for many signaling processes and cellular function. Resolving proteins within clusters with both high temporal and spatial resolution has been challenging for both optical and atomic force microscopy.  The challenge for atomic force microscopy has been deformation of the sample due to the minimum force of imaging and mechanical limitations of the scanners to scan quickly. I will present innovations from my group to address both of these issues. I will discuss different AFM control theories and why reducing interaction force is best accomplished through cantilever innovation. Then, I will present my groups efforts with both nanowire cantilevers and encased cantilevers, the latter of which have 10 times higher sensitivity than regular cantilever in solution. Lastly, I will discuss a new scanning mode we developed and how it enables much higher scan speeds.

Biosketch

Paul Ashby graduated Magna Cum Laude from Westmont College and subsequently did his Ph.D. at Harvard University with Charles Lieber investigating interfacial and intermolecular forces using Chemical Force Microscopy as an NSF fellow.  Based on that work he was a founder of Potentia Pharmaceuticals, which won the Harvard Business plan competition. He moved back to California to join the Molecular Foundry, a DOE Nanoscience Research center, as a jump start postdoc.  Continuing as a staff scientist, his research program has focused on developing gentle high-speed Atomic Force Microscopy for investigating soft dynamic materials in solution.

Seminar Date