Scientists learn how to 'out run damage' with imaging technique

Feb 21, 2012

Over the decades X-ray crystallography has been fundamental in the development of many scientific fields. The method has revealed the structure and function of many biological molecules, including vitamins, drugs, proteins and nucleic acids such as DNA. However, in order to obtain good data, large single crystals are required. These are often nearly impossible to grow. There also is the problem that X-rays damage delicate biological samples.

"From the beginning, the resolution of images recorded by biologists has been limited by damage due to the radiation used," said physicist John C. H. Spence, a Regents' Professor in physics at Arizona State University. "But what happens if a pulse of imaging radiation is used that terminates before damage begins, yet contains sufficient photons to generate a useful scattering pattern?"

Indeed, results of such a method are being reported by Spence at the annual meeting in Vancouver, Canada. Spence presented his findings today (Feb. 17) during a special session on "Imaging and Controlling with Ultrashort Laser Pulses."

Many in the scientific community didn't believe such a method could work. Yet, said Spence "The experiments of Henry Chapman's (University of California, Davis) group using lithographed structures and soft (i.e. long wavelength) X-rays had shown that if we could 'out-run the damage,' this might indeed be a useful path to damage-free imaging at . In my lab we were thinking about the data analysis, and building the hydrated protein-beam injector device, a bit like an ink-jet printer, to spray the molecules across an X-ray laser. This snap-shot method should eventually allow us to make movies of molecular machines at work."

Spence joined forces with Chapman and many collaborators to recently demonstrate serial snapshot femtosecond (10-15 of a second) diffraction (SFX) from nanocrystals using the world's first hard X-ray laser. The photosystem I (PSI) came from Professor Petra Fromme's lab in ASU's Department of Chemistry and Biochemistry.

"These are early days for femtosecond diffractive imaging," noted Spence, who provided the theory and much of the data analysis. "But first indications are that high-resolution data can now be obtained at the nanoscale by this method. If we can indeed 'outrun' the many radiation-damage processes in this way, it will open the way to future experiments on laser-excited samples, 3-D image reconstruction and a host of other experiments on fast imaging, all directed to the grand challenge of obtaining movies showing molecules at work."

Explore further: Electric vehicles could stabilize large disturbances in power grid

Related Stories

Jet-propelled Imaging for an Ultrafast Light Source

Aug 04, 2009

(PhysOrg.com) -- John Spence, a physicist at Arizona State University, is a longtime user of the Advanced Light Source at Lawrence Berkeley National Laboratory, where he has contributed to major advances in lensless imaging. ...

Fastest X-ray images of tiny biological crystals

Jan 05, 2012

(PhysOrg.com) -- An international research team headed by DESY scientists from the Center for Free-Electron Laser Science (CFEL) in Hamburg, Germany, has recorded the shortest X-ray exposure of a protein crystal ...

Jet-propelled imaging for an ultrafast light source

Jul 29, 2009

John Spence, a physicist at Arizona State University, is a longtime user of the Advanced Light Source at Lawrence Berkeley National Laboratory, where he has contributed to major advances in lensless imaging. ...

Recommended for you

Measuring NIF's enormous shocks

2 hours ago

NIF experiments generate enormous pressures—many millions of atmospheres—in a short time: just a few billionths of a second. When a pressure source of this type is applied to any material, the pressure ...

How the hummingbird achieves its aerobatic feats

Nov 23, 2014

(Phys.org) —The sight of a tiny hummingbird hovering in front of a flower and then darting to another with lightning speed amazes and delights. But it also leaves watchers with a persistent question: How ...

New terahertz device could strengthen security

Nov 21, 2014

We are all familiar with the hassles that accompany air travel. We shuffle through long lines, remove our shoes, and carry liquids in regulation-sized tubes. And even after all the effort, we still wonder if these procedures ...

CERN makes public first data of LHC experiments

Nov 21, 2014

CERN today launched its Open Data Portal where data from real collision events, produced by experiments at the Large Hadron Collider (LHC) will for the first time be made openly available to all. It is expected ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.