Open AccessX‐ray microdiffraction and conventional diffraction from frozen‐hydrated biological specimens
Author(s) -
Inoue Katsuaki,
Yagi Naoto,
Iwamoto Hiroyuki,
Fujisawa Tetsuro
Publication year - 2005
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s090904950501352x
Subject(s) - materials science , diffraction , optics , liquid nitrogen , beamline , micrometer , biological specimen , cryostat , beam (structure) , chemistry , quantum mechanics , physics , superconductivity , organic chemistry
A system for recording microdiffraction patterns from micrometer‐sized quick‐frozen hydrated biological specimens at the high‐flux beamline BL40XU of SPring‐8 is described. The optics consists of a pair of pinholes drilled into tantalum substratum, with a defining aperture of diameter 2 µm. The frozen specimens are placed in an in‐vacuum cryochamber mounted on a three‐axis goniometer, where the specimens are stably held at a liquid‐nitrogen temperature (∼74 K). A beam size of 1.5 µm (full width at half‐maximum) is attained at the sample position. By using this system, diffraction patterns have been recorded from an isolated single myofibril (diameter ∼3 µm) of an insect flight muscle in an area equivalent to a single sarcomere (length ∼3 µm). The technique is potentially applicable to other micrometer‐sized hydrated biological specimens, which are more susceptible to radiation damage than dry synthetic polymers or biopolymers. The quick‐freezing of biological specimens has also been proven useful in reducing the specimen volume in the beam in conventional diffraction recordings.