Showing papers by "David Eisenberg published in 1974"
TL;DR: In this paper, a method for rapid and accurate alignment of macromolecular crystals for precession-camera photography, which reduces exposure time of crystals to a fraction of that for traditional alignment procedures, is reported.
Abstract: A method for rapid and accurate alignment of macromolecular crystals for precession-camera photography, which reduces exposure time of crystals to a fraction of that for traditional alignment procedures, is reported. Alignment is achieved with a `cone-axis oscillation' photograph in which the X-ray film is substituted for the layer-line screen, and the precession motion is permitted to oscillate through only part of its total path. The developed film displays a set of concentric circles whose common center is displaced from the film center by an amount related to the angular errors of alignment. With a single cone-axis oscillation photograph, correction of initial alignment errors up to 25° can be made to within 30′ and correction of alignment errors of 10° to within 10′. The method has been tested successfully on crystals having unit-cell edges up to 380 A. Simple algorithms for application of the method are presented.
3 citations