The fundamental idea behind this Congress is simple, i.e., that freezing cells is the best way to preserve their ultrastructure in a state that is as close to native as possible. However, between the frozen cell and the image of that cell in the electron microscope, there are a number of serious technical challenges that must be met to retain and image that near-native structure. The Congress will show what researchers and manufacturers are doing to meet those challenges. We will start with the primary freezing process, including high pressure freezing and plunge freezing, because all subsequent processing relies on having frozen-hydrated, or vitreous specimens. Cryo-EM of specimens in vitreous ice (from molecules to whole cells and organelles) will be discussed, as well as how to cut vitreous cryosections of samples that are too large to image whole. We will hear about the state-of-the-art for coating frozen samples and viewing them in the Cryo-SEM, or as freeze-fracture replicas. Three-dimensional imaging of specimens using cryo-electron tomography, and in the SEM by extracting surfaces from stereopair images will be discussed. The new technique of sequential milling with the focused ion beam, followed by imaging in the cryo-SEM or cryo-TEM will be included. Cryo-immobilization followed by freeze-substitution and embedding for sectioning will be covered, especially in the context of cellular tomography and 3-D imaging. Advances in immunolabelling of cryo-prepared specimens will be discussed, including stategies for converting GFP and other reporter molecules into electron dense probes. In general, all the best practices for high-resolution cryo-microscopy using both SEM and TEM will be covered.

The two-day Congress will combine how-to lectures with live demonstrations of the latest preparation equipment. It will start Saturday afternoon with an opening reception followed by key background lec-tures, and continue all day Sunday with lectures and demonstrations.

This symposium was originally planned by the late Stan Erlandsen, MSA Past President and high-resolution cryo-SEM expert. It is held in his honor.