Forum 04/30/2009

“Getting started in Cellular EM: an introduction to high pressure freezing and vitreous cryosectioning”

Kent McDonald – Director, Electron Microscope Lab, University of California Berkeley

In recent years several labs have produced exciting data from whole vitrified cells by cryo-electron tomography. But the number of cells that can be treated this way are relatively few and larger cells, even most bacteria, have to be cryosectioned to achieve good resolution. In making the transition from whole cells to vitreous sections one encounters a number of challenges: cryofixation by high pressure freezing instead of plunge freezing, the process of cutting the sections, and, last but not least, getting the sections properly attached to an EM grid. In this presentation we will review some of the latest instruments and techniques that have been developed to address these challenges.