TY - JOUR T1 - Long shelf-life streptavidin support-films suitable for electron microscopy of biological macromolecules JF - bioRxiv DO - 10.1101/054452 SP - 054452 AU - Bong-Gyoon Han AU - Zoe Watson AU - Hannah Kang AU - Arto Pulk AU - Kenneth H. Downing AU - Jamie Cate AU - Robert M. Glaeser Y1 - 2016/01/01 UR - http://biorxiv.org/content/early/2016/06/12/054452.abstract N2 - We describe a rapid and convenient method of growing streptavidin (SA) monolayer crystals directly on holey-carbon EM grids. As expected, these SA monolayer crystals retain their biotin-binding function and crystalline order through a cycle of embedding in trehalose and, later, its removal. This fact allows one to prepare, and store for later use, EM grids on which SA monolayer crystals serve as an affinity substrate for preparing specimens of biological macromolecules. In addition, we report that coating the lipid-tail side of trehalose-embedded monolayer crystals with evaporated carbon appears to improve the consistency with which well-ordered, single crystals are observed to span over entire, 2 μm holes of the support films. Randomly biotinylated 70 S ribosomes are used as a test specimen to show that these support films can be used to obtain a high-resolution cryo-EM structure. ER -