title: Effects of radiation damage with 400-kV electrons on frozen, hydrated actin bundles.
abstract: Electron images can be used to provide amplitudes and phases for the structural determination of biological specimens. Radiation damage limits the amount of structural information retrievable by computer processing. A 400-kV electron microscope was used to investigate radiation damage effects on frozen, hydrated actin bundles kept at -168 degrees C. The quality of phases within and among images in a damage series was evaluated quantitatively out to 16 A resolution. It was found that the phases of structure factors with good signal-to-noise ratio (IQ less than or equal to 4) can be reliably retrieved from images taken at a cumulative dose of at least 25 electrons/A2.
authors.affiliation: W. M. Keck Center for Computational Biology, Baylor College of Medicine, Houston, Texas 77030.
authors.forename: M F
authors.initials: MF
authors.lastname: Schmid
authors.forename: J
authors.initials: J
authors.lastname: Jakana
authors.forename: P
authors.initials: P
authors.lastname: Matsudaira
authors.forename: W
authors.initials: W
authors.lastname: Chiu
mesh_terms: D000199:Actins / Q000737:chemistry / Q000528:radiation effects* / Q000648:ultrastructure; D003461:Crystallography; D004583:Electrons; D005615:Freezing; D007091:Image Processing, Computer-Assisted; D008854:Microscopy, Electron; D013696:Temperature; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D000199:Actins; D014867:Water