Crystals on the cover of Acta Cryst. F.
crystallization; crystal images
A device has been developed to optimize crystal-growth conditions by experiments in a single drop.
A completely new crystal-growth device has been developed that permits charting a course across the phase diagram to produce crystalline samples optimized for diffraction experiments. The utility of the device is demonstrated for the production of crystals for the traditional X-ray diffraction data-collection experiment, of microcrystals optimal for data-collection experiments at a modern microbeam insertion-device synchrotron beamline and of nanocrystals required for data collection on an X-ray laser beamline.
crystal growth; single-drop optimization; Xtal-Controller
The Editors highlight the crystals featured on the cover and a new series of articles.
The Editors of Acta F look forward to 2014.
title change; editorial
crystallization communications; editorial
Excitation of intrinsic fluorescence at wavelengths longer than 300 nm is effective in the detection of protein crystals in crystallization trials set up in the most commonly used hardware.
It is well known that most proteins and many other biomolecules fluoresce when illuminated with UV radiation, but it is also commonly accepted that utilizing this property to detect protein crystals in crystallization setups is limited by the opacity of the materials used to contain and seal them. For proteins, this fluorescence property arises primarily from the presence of tryptophan residues in the sequence. Studies of protein crystallization results in a variety of setup configurations show that the opacity of the containment hardware can be overcome at longer excitation wavelengths, where typical hardware materials are more transparent in the UV, by the use of a powerful UV-light source that is effective in excitation even though not at the maximum of the excitation response. The results show that under these circumstances UV evaluation of crystallization trials and detection of biomolecular crystals in them is not limited by the hardware used. It is similarly true that a deficiency in tryptophan or another fluorescent component that limits the use of UV light for these purposes can be effectively overcome by the addition of fluorescent prostheses that bind to the biomolecule under study. The measurements for these studies were made with a device consisting of a potent UV-light source and a detection system specially adapted (i) to be tunable via a motorized and software-controlled absorption-filter system and (ii) to convey the excitation light to the droplet or capillary hosting the crystallization experiment by quartz-fibre light guides.
UV fluorescence; detection of protein crystals
crystallization ontology; editorial
The problem of undercounting of citations that are published only in supplementary material is studied for the journals Nature, Science, Cell and the Proceedings of the National Academy of Sciences (USA).
citations; supplementary material; editorial