1. Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
2. The Boulder Laboratory for 3D Electron Microscopy of Cells, Department of Molecular, Cellular, and Developmental Biology, University of Colorado–Boulder, Boulder, CO 80309
3. Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109
4. Department of Pathology and Laboratory Medicine, University of Wisconsin–Madison, Madison, WI 53706
5. Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706