What is X-Ray Crystallography?
X-ray crystallography is an extremely precise, but also difficult and expensive means of imaging the exact structure of a given molecule or macromolecule in a crystal lattice. Because a diverse set of materials produce crystals, including salts, metals, minerals, semiconductors, and various inorganic, organic, and biological molecules, x-ray crystallography is essential to many scientific fields. A crystal is any regularly repeating arrangement of unit cells which range in size from less than 100 atoms — small-molecule crystallography — to tens of thousands — macromolecular crystallography). X-ray crystallography is famous for being the tool first used to discover the structure of DNA, but it was also used to determine the structure of diamond, table salt, penicillin, numerous proteins, and entire viruses. In all, over 400,000 structures have been described using x-ray crystallography. These can be found in the Cambridge Structure Database. To analyze a sample using x-ray crystallograp
X-ray crystallography is a complex and dynamic field that has been associated with several of sciences major breakthroughs in the second half of the 20th century. Using X-ray crystal data, Drs. James Watson and Francis Crick were able to determine the helical structure of DNA in 1953. More recently, in 1998, Dr. Peter Kim, was able to determine the structure of GP120, a key protein responsible for the HIV infection process. This structure has provided scientists the means for producing new drugs, preventing the deadly HIV infection. X-ray crystallography is a scientific technique that is very similar to medical X-rays. Instead of using an X-ray machine and peering into a person, X-ray crystallography uses X-ray radiation to determine the shape of a molecule that has been crystallized into a solid. All solids have a subatomic lattice structure that gives the molecule its solid properties. A well-known crystalline solid that has a simple lattice structure is table salt, NaCl. Understandi
X-ray crystallography is an experimental technique that uses the fact that X-rays are diffracted by crystals. It is not an imaging technique. X-rays have the correct wavelength to be scattered by the electron cloud of an atom of comparable size. Based on the diffraction pattern obtained from the regular assembly of molecules or atoms in the crystal, the electron density can be reconstructed. Additional phase information extracted either from the data, or from extra experiments, must be supplied to complete the reconstruction. Why Crystallography? The knowledge of accurate molecular structures is a prerequisite for drug design and for structure based functional studies to aid the development of effective therapeutic agents and drugs. Crystallography can reliably provide the answer to many structure related questions, from global folds to atomic details of bonding. In contrast to NMR, which is an indirect spectroscopic method, no size limitation exists for the molecule or complex to be s
