Brightest light in universe to examine lung cancer cells

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http://www.hindu.com/thehindu/holnus/00 ... 071440.htm

By James Randerson

London, July 7 (Guardian News Service): It sounds like the stuff of post-millennial conspiracy theorists. New Year 2007 will see the arrival of a light brighter than anything in the known universe at a field in Oxfordshire, southern England. But this is noSpielbergesque alien visitation. A GBP250m machine will be switched on,which is designed to help scientists peer in more detail than ever beforeat the fine structure of cells.

The Diamond synchrotron's predecessor had a hand in everything fromdesigning the anti-cancer drug Herceptin to improving chocolate manufactureand working out whether Beethoven was poisoned. But because Diamond is amillion times brighter it will allow scientists to look at tiny structurein much more detail.

It will allow us to ``look into the dark corners of this world with muchmore precision'', said Gerhard Materlik, chief executive of the project.Most of the funding for the machine has come from the UK government whilethe research charity the Wellcome Trust is providing the rest.

Diamond is a particle accelerator which boosts packets of 10m electronsto close to the speed of light and whizzes them round a magnetic ring overhalf kilometre in circumference. As they spin they give offelectro-magnetic radiation such as visible light, x-rays and infra-redradiation. Scientists use these beams of radiation to home in on thedetails of tiny structures.

It is being built in tandem with a complementary machine in Francecalled Soleil. This will specialise in different applications, andscientists will make use of both. The machines are the largest publiclyfunded fundamental research projects in the two countries.

Dr Josep Sule-Suso, a cancer specialist at the University Hospital ofNorth Staffordshire, England, plans to use Diamond to study the way lungcancer cells react to drugs. He is using Diamond's predecessor to bombardindividual cells with infra-red light and watches how the light they absorbchanges. The absorption changes are caused by chemical changes in thecells.

``It has huge potential,'' said Dr Sule-Suso. He envisages being able toscreen samples from patients for tumours that have yet to show symptoms orto examine tissue after chemotherapy to check the cancer has beendestroyed.

The machine has even been used to settle a forensic puzzle nearly twocenturies old. By examining locks of Beethoven's hair, scientists foundevidence of large quantities of lead, suggesting the composer's death wasbrought on by lead poisoning.

Another application is in studying the shape of molecules by bombardingthem with x-rays. ``You can pick apart materials without having to openthem up,'' said Sarnjeet Dhesi, a researcher at Diamond. Radiation hittingthe molecules is diffracted and produces a pattern on the far side of thex-ray beam that can be used to work out the molecule's structure. This washow Watson and Crick worked out the double-helical structure of DNA.

The great advantage of Diamond is that it will allow researchers to lookat the structure of awkward proteins which span the outer coat of livingcells, the membrane. These proteins are often what invaders such as virusesuse to enter the cell and understanding how this happens can be vital todesigning a vaccine.

But membrane proteins have proved extremely difficult to visualise usingx-ray sources. Diamond's extra brightness means that scientists only need asmall quantity of the protein, making them much easier to study.