Improve X-Ray Crystalography - Current Work

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In summary, Sigourney Weaver narrated the NOVA show about photo 51, an x-ray diffraction photo of the DNA molecule, the first of its kind.
  • #1
Entropia
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does anybody know of any current work that is being done to improve x-ray crystalography techniques?
 
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  • #2
No, but Sigourney Weaver narrated the NOVA show about photo 51, an x-ray diffraction photo of the DNA molecule, the first of its kind.
 
  • #3
she was great in The Year of Living Dangerously
where is Fox? I like imagining places up north
Schild means forehead in German
there is a fine touch of whimsey to signing God Save the Empire
with the silhouette of an ironical English moviedirector
I will look for something online about the xray DNA picture
why was it a first-ever?
 
  • #4
Am not sure just how recent it has to be considered "current" for your purposes, but some of the methods which have been introduced in the past decade or so (esp. in protein crystallography) have been:

1.) cryocooling, in which you add in some cryoprotective agents and then do your x-ray data collection in the beam at very low temperatures. This will decrease crystal degradation and reduce the rate at which free radicals will diffuse through the crystal (after all, you are pumping x-ray radiation through the thing).

2.) lipidic cubic phase crystallization. Mainly for proteins (although I guess you could do this for anything which is somewhat hydrophobic and doesn't crystallize easily with more traditional methods), you put your sample into a lipidic solution with a little bit of water and essentially the hydrophobic packing leads to nucleation which leads to crystal growth.

3.) Multiwavelength Anomalous Dispersion (MAD) is a method for solving the phase problem by using heavy atoms (similar to MIR) and a spectrum of wavelengths to determine structure. Again, used especially by protein/macromolecular crystallographers. Pioneered by Wayne Hendrickson (now at Columbia Univ.)

4.) You might want to discuss two somewhat recent developments in structure refinement, namely the usage of the R(free) value and the increasing usage of molecular modeling techniques (simulated annealing, molecular dynamics, and the like) to improve the quality of the final structure.

I admit most of these have a protein crystallography bias, as that's what I'm most familiar with (such as it is), but hopefully this will give you some ideas.
 
  • #5
On a side note, how dangerous is it to be in the room with an operating device? I'm doing some HVAC work for U Penn in a room they do x-ray crystallography.
 
  • #6
It's probably OK as long as you follow whatever safety guidelines the lab has in place. The x-ray lab at my old university was staffed by full time scientists, so never spent much time there and the x-ray lab at my current school is not particularly relevant to my work, so I don't spend any time there. I would definitely make sure to ask them that they turn off/remove anything that might be dangerous or valuable and for anything you should know about it. I would think it would be fine as long as you do that. I mean, it's not like you're going to be doing any work when they have the beam turned on. Right?
 
  • #7
Originally posted by Entropia
does anybody know of any current work that is being done to improve x-ray crystalography techniques?

Which technique are you interested in?

For Debye-Scherrer methods, you typically want to blast a pulverized sample with a white spectrum and hope that you get as many different wavelengths to interact with as many different crystal orientations as possible. It seems logical to assume that the best way to improve such a technique would be to make a broader, flatter x-ray source.

For rotating-crystal methods, you ideally want a very specific wavelength x-ray to interact with a very specific crystal orienation. So, the best way to improve this method would be to develop a good tunable, narrow-band x-ray source and better stepping motors for turning the crystal.

For the Laue method, you usually want to hit a stationary crystal with a very white x-ray source, and try to detect all the diffracted rays. This is traditionally done by surrounding the crystal with a spherical shell of film. I suppose the best way to improve this technique would be to improve the whiteness of the x-ray source and perhaps improve the stepping motors as well.

eNtRopY
 
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  • #8
"why was it a first-ever?"

Guess it couldn't be the first ever, otherwise it would be photo 1 not 51, but the NOVA show said that she was the first to photograph DNA with x-ray crystallography, and interpret the diffraction pattern by hand. She had to run the x-ray camera for up to 100 hours per frame, which gave her cancer at age 36. Watson & Crick so famous for 'discovery' of DNA used her work without her knowledge to construct their models.

Fox is north of Fairbanks about 5 miles.
 
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  • #9
You should have a look on the website of the international cristallogarphy union.

www.iucr.org
 

1. What is X-Ray Crystalography?

X-Ray Crystalography is a scientific technique used to determine the atomic and molecular structure of a crystalline material. It involves shining an X-ray beam onto a crystal and analyzing the diffraction patterns produced to determine the arrangement of atoms within the crystal.

2. Why is it important to improve X-Ray Crystalography?

Improving X-Ray Crystalography allows for more accurate and detailed analysis of the structure of materials, which is crucial for understanding their properties and potential applications. It also helps to advance various fields of science, such as chemistry, biology, and materials science.

3. What are the current challenges in X-Ray Crystalography?

One of the main challenges in X-Ray Crystalography is obtaining high-quality crystals for analysis. Crystallization is a complex and unpredictable process, and not all materials can form crystals suitable for X-ray diffraction. Another challenge is the resolution limit, which determines the level of detail that can be seen in the diffraction patterns.

4. How can X-Ray Crystalography be improved?

X-Ray Crystalography can be improved through advancements in instrumentation, such as more powerful X-ray sources and detectors, which allow for higher resolution and faster data collection. Additionally, new techniques and software for data analysis can improve the accuracy and efficiency of the process.

5. What are the potential future developments in X-Ray Crystalography?

Some potential future developments in X-Ray Crystalography include the use of free-electron lasers, which can produce extremely intense and short X-ray pulses, allowing for the analysis of smaller and more fragile crystals. Another area of research is in-situ and time-resolved crystallography, which allows for the observation of dynamic processes, such as chemical reactions or protein folding, in real-time.

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