SciLifeLab Fellows seminar series: Peering deeply into cells with cryo-STEM tomography


Speaker: Sharon Wolf, Weizmann Institute of Science.

Abstract

CryoSTEM tomography (CSTET) is a method for elucidating structure and elemental composition of vitrified cells, in regions up to  around 1 micron in thickness. Because STEM imaging is an incoherent process, useful signal can be obtained from both elastically and inelastically scattered electrons, providing very  efficient dose utilization. Dynamic focusing during rastering of the beam provides high tilt images that are in focus in all areas of the image.  The contrast in STEM images is dependent on elemental composition as well as sample density. A variety of detectors collect the signals at specific ranges of scattering angles, so that both bright-field and dark-field images can be obtained simultaneously with the same dose, and provide complementary information.  In addition, on-the-spot measurement of energy-dispersive X-ray spectroscopy provides elemental analysis in specific cellular locations. Examples from both bacteria and human cells will be discussed.

Bio

Sharon G. Wolf received her PhD in Structural Chemistry from the Weizmann Institute of Science in 1991, under Prof. Leslie Leiserowitz. She studied the structure of lipids and amphipathic molecules at the air/water interface using synchrotron specular reflectivity and grazing incidence diffraction. During her postdoctoral studies in the group of Dr. Ken Downing at the Lawrence Berkeley Laboratories, she and fellow postdoc Eva Nogales elucidated the structure of the protein tubulin using electron crystallography. In 1997, Sharon returned to the Weizmann Institute, and is currently a Senior Research Fellow and Head of the Electron Microscopy Unit there. In recent years, Sharon has been developing cryoSTEM tomography for the study of thicker regions of vitrified, unperturbed biological cells.

This seminar is part of a seminar series hosted by SciLifeLab Fellows

Date: April 20

Time: 11:00-12:00

Venue: Air auditorium, SciLifeLab Solna

Host: Alexey Amunts