Electron Microscopy of Cells: A New Beginning for a New Century

It is widely acknowledged that EM of macromolecules is entering a new phase of productivity (for review see Nogales and Grigorieff 2001). It is less well known that comparable innovations are afoot in cellular EM. Studies of biological “ultra-structure” were of key importance in the early years of cell biology, but more recently their importance has waned significantly. This change has been largely because much of what could be seen by classical techniques for EM has long since been described; it has also derived from the cost of EM in both time and money and the innovations that have recently revolutionized light microscopy, making it ever more powerful for the study of living cells. However, recent improvements in both methods and instrumentation for EM are now allowing the structure of organelles and cellular subsystems to be characterized with...