Recording of Harald Hess’s talk on June 24, 2021, at the EPFL Seminar Series in Imaging.
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The EPFL Seminar Series in Imaging is run by EPFL Center for Imaging: [ Ссылка ]
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Abstract. 3D electron microscopy data can be acquired by Focused Ion Beam Scanning Electron Microscopy FIB-SEM where fine sequence of 4-8 nm increments are ablated off of a sample surface and each such surface is imaged with the SEM. At the finest resolution and with month long stable operation, comprehensive whole cells can be acquired that transcends the limited cut section views of traditional TEM used in biology. Several examples of such data are presented along with the potential that segmentation offers to explore and formulate biological questions. Correlative microscopy can be achieved by a cryogenic protocol where samples are vitrified, imaged with PALM or SIM at low temperatures followed by EM staining and FIBSEM. A 3D registration procedure can keep most position errors between PALM and EM data at ~ 30 nm. Examples validating the approach with mitochondrial and endoplasmic reticulum labels are presented along with examples showcasing how unknown vesicle types and other structures can be identified by an associated protein.
Biography. Harald Hess is an experimentalist who has contributed to several fields across physics and biology. After a PhD in Physics at Princeton in 1982, Harald Hess pursued hydrogen atom trapping and its Bose-Einstein condensation, BEC, at MIT as a postdoc. There he conceived of evaporative cooling as the means to achieve BEC which contributed to the 2001 Nobel Prize in Physics. At Bell Labs he developed various low temperature scanning probe microscopes to visualize diverse physics phenomenon, such as vortices in superconductors, at Bell Labs. After 1997 he spent 8 years in industry developing advanced equipment for hard disk drive and semiconductor inspection and production. In 2005 he and a colleague, Eric Betzig, learned about photoactivatable fluorescent proteins and invented PALM (photo-activated localization microscopy) to reveal details of cell structure beyond the diffraction limit. It was built in a La Jolla condo, tested at the National Institute of Health and contributed to the 2014 Nobel Prize in Chemistry. At Janelia Research Campus of Howard Hughes Medical Institute he extended PALM to a 3D super-resolution microscopy and is exploring its application for cell biology research. There he is also developing 3D electron microscopy techniques for volume imaging of cells and neural tissue. and an ion beam polish cycle to acquire such three-dimensional pictures.
