Berthold Kastner, Niels Fischer, Monika Mariola Golas, Bjoern Sander, Prakash Dube, Daniel Boehringer, Klaus Hartmuth, Jochen Deckert, Florian Hauer, Elmar Wolf, Hannes Uchtenhagen, Henning Urlaub, Franz Herzog, Jan Michael Peters, Dietmar Poerschke, Reinhard Lührmann, Holger Stark
We developed a method, named GraFix, that considerably improves sample quality for structure determination by single-particle electron cryomicroscopy (cryo-EM). GraFix uses a glycerol gradient centrifugation step in which the complexes are centrifuged into an increasing concentration of a chemical fixation reagent to prevent aggregation and to stabilize individual macromolecules. The method can be used to prepare samples for negative-stain, cryo-negative-stain and, particularly, unstained cryo-EM.
January 2008: Nature Methods