Diffraction Quality Crystals
Diffraction Quality Crystals - Related Videos
08:00
Growing Crystals for X-ray Diffraction Analysis
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2023
Source: Laboratory of Dr. Jimmy Franco - Merrimack College X-ray crystallography is a method commonly used to determine the spatial arrangement of atoms in a crystalline solid, which allows for the determination of the three-dimensional shape of a molecule or complex. Determining the three-dimensional structure of a compound is of particular importance, since a compound's structure and function are intimately related. Information about a compound's structure is often used to explain its...
08:14
Single Crystal and Powder X-ray Diffraction
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2023
Source: Tamara M. Powers, Department of Chemistry, Texas A&M University X-ray crystallography is a technique that uses X-rays to study the structure of molecules. X-ray diffraction (XRD) experiments are routinely carried out with either single-crystal or powdered samples. Single-crystal XRD: Single-crystal XRD allows for absolute structure determination. With single-crystal XRD data, the exact atomic positions can be observed, and thus bond lengths and angles can be determined. This...
09:35
Microcrystallography of Protein Crystals and In Cellulo Diffraction
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Cited by 9 •
2017
A protocol is presented for X-ray crystallography using protein microcrystals. Two examples analyzing in vivo-grown microcrystals after purification or in cellulo are compared.
09:31
X-ray Diffraction
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2023
Source: Faisal Alamgir, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA X-ray diffraction (XRD) is a technique used in materials science for determining the atomic and molecular structure of a material. This is done by irradiating a sample of the material with incident X-rays and then measuring the intensities and scattering angles of the X-rays that are scattered by the material. The intensity of the scattered X-rays are plotted as a function of the...
07:42
On-Chip Crystallization and Large-Scale Serial Diffraction at Room Temperature
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Cited by 4 •
2022
This contribution describes how to set up protein crystallization on crystal-on-crystal devices and how to perform automated serial data collection at room temperature using the on-chip crystallization platform.
FAQs
The ordered lattice produces a reproducible diffraction pattern when exposed to X-rays or other radiation. Researchers measure the intensities of the resulting spots and use them to calculate an electron-density map. This map reveals how atoms are arranged within the crystallized protein, nucleic acid, or molecular complex, providing the structural basis for interpreting biological function.
A well-ordered lattice allows many repeated molecular units to scatter radiation in a coordinated way, generating measurable spots rather than an uninformative signal. The quality of that pattern affects how reliably electron density can be calculated. Consequently, crystal growth must balance orderly assembly with conditions that preserve the molecule’s native structure.
Concentration, pH, temperature, and precipitant conditions all influence how purified biological molecules assemble into a lattice. Changing one factor can shift the balance between remaining dissolved and forming an ordered solid. Researchers therefore optimize these variables to favor crystal formation while avoiding conditions that disrupt molecular structure or produce poorly ordered material.
The key distinction is the usefulness of the diffraction pattern, not simply whether visible crystals appear. Diffraction-quality material has sufficient internal order to generate measurable spots whose intensities support electron-density calculations. A crystal that forms but lacks adequate order may not provide structural information, even if its overall shape appears suitable.
Researchers begin with a purified protein, nucleic acid, or complex and place it under controlled crystallization conditions. They vary concentration, pH, temperature, and precipitants to identify conditions that promote ordered assembly. Candidate crystals are then evaluated by their diffraction behavior, with the most useful patterns selected for structure calculation and biological interpretation.
They are useful when researchers need three-dimensional structural information about a biological molecule or complex. The resulting structures can clarify enzyme mechanisms, show how ligands bind, and reveal molecular interactions. These insights connect atomic-level arrangement with biological function and can also support structure-guided drug-design studies.
An electron-density map provides a spatial representation that researchers interpret to determine the arrangement of atoms in the crystallized material. In biological crystallography, that arrangement can expose features of proteins, nucleic acids, or complexes relevant to activity and binding. Its usefulness depends on diffraction data from a sufficiently ordered lattice and preserved molecular structure.
Structural conclusions are biologically meaningful only when the crystallized sample retains the relevant molecular organization. Conditions that encourage assembly but alter the molecule can produce a lattice that does not represent its functional state. Maintaining native structure therefore links the measured diffraction data to valid interpretations of enzyme action, ligand recognition, or molecular interaction.