X-Rays Take Groundbreaking Virus Portrait

July 14, 2008 -- Beyond diagnosing broken bones, X-rays could soon help doctors develop antiviral drugs.

By focusing powerful X-rays onto a herpes virus, scientists from the University of California, Los Angeles, have created the first image of a virus without the aid of stains or dyes.

The technique, known as X-ray diffraction microscopy, could lead to new drugs for a variety of diseases.

A similar version of the technology, known as X-ray crystallography, has been used for years to determine the structure of many important proteins, including the double helix of DNA.

"This is an enormously important technique," said John Miao of UCLA, the lead researcher on the project. "Lots of Nobel Prizes have been awarded because of this."

The problem with X-ray crystallography is that it only works on crystals, which have precise arrangements of identical (or nearly identical) units. DNA and some proteins are repetitive enough to be made into crystals.

Other proteins, particularly those found on a cell's membrane, can't be crystallized because they are too flexible and variable. Whole cells can't be crystallized either.

"Cells are just like humans, and no two humans are exactly alike," said Miao.

Miao and his colleagues worked around this limitation by using what are currently the most powerful X-rays on Earth, located at the SPring-8 synchrotron in Japan.