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Title: A high-transparency, micro-patternable chip for X-ray diffraction analysis of microcrystals under native growth conditions

A highly X-ray-transparent, silicon nitride-based device has been designed and fabricated to harvest protein microcrystals for high-resolution X-ray diffraction data collection using microfocus beamlines and XFELs. Microcrystals present a significant impediment to the determination of macromolecular structures by X-ray diffraction methods. Although microfocus synchrotron beamlines and X-ray free-electron lasers (XFELs) can enable the collection of interpretable diffraction data from microcrystals, there is a need for efficient methods of harvesting small volumes (<2 µl) of microcrystals grown under common laboratory formats and delivering them to an X-ray beam source under native growth conditions. One approach that shows promise in overcoming the challenges intrinsic to microcrystal analysis is to pair so-called ‘fixed-target’ sample-delivery devices with microbeam-based X-ray diffraction methods. However, to record weak diffraction patterns it is necessary to fabricate devices from X-ray-transparent materials that minimize background scattering. Presented here is the design of a new micro-diffraction device consisting of three layers fabricated from silicon nitride, photoresist and polyimide film. The chip features low X-ray scattering and X-ray absorption properties, and uses a customizable blend of hydrophobic and hydrophilic surface patterns to help localize microcrystals to defined regions. Microcrystals in their native growth conditions can be loaded into the chips with amore » standard pipette, allowing data collection at room temperature. Diffraction data collected from hen egg-white lysozyme microcrystals (10–15 µm) loaded into the chips yielded a complete, high-resolution (<1.6 Å) data set sufficient to determine a high-quality structure by molecular replacement. The features of the chip allow the rapid and user-friendly analysis of microcrystals grown under virtually any laboratory format at microfocus synchrotron beamlines and XFELs.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ; ;  [3] ;  [6] ;  [2]
  1. University of California, Berkeley, CA 94720 (United States)
  2. (United States)
  3. Stanford University, Stanford, CA 94305 (United States)
  4. Argonne National Laboratory, Argonne, IL 60439 (United States)
  5. Johns Hopkins University, Baltimore, MD 21205 (United States)
  6. Johns Hopkins University School of Medicine, Baltimore, MD 21205 (United States)
Publication Date:
OSTI Identifier:
22420137
Resource Type:
Journal Article
Resource Relation:
Journal Name: Acta Crystallographica. Section D: Biological Crystallography; Journal Volume: 71; Journal Issue: Pt 10; Other Information: PMCID: PMC4601365; PMID: 26457423; PUBLISHER-ID: gm5039; OAI: oai:pubmedcentral.nih.gov:4601365; Copyright (c) Murray et al. 2015; This is an open-access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
Denmark
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CRYSTAL GROWTH; CRYSTALLOGRAPHY; EQUIPMENT; SILICON NITRIDES; SYNCHROTRONS; TEMPERATURE RANGE 0273-0400 K; X RADIATION; X-RAY DIFFRACTION