St Andrews science in national spotlight

Sunday 23 June 2002

Imagine a beam of light that can trap and manipulate microscopic objects like the tractor beam in Star Trek. Science fiction? No, science fact, thanks to the ‘optical tweezers’ used at the School of Physics and Astronomy at the University of St Andrews.

Dr Kishan Dholakia led the team that produced the compact and easy to use device, which employs lasers to both move and rotate small objects with incredible precision and accuracy. The creations will be showcased among the best of the UK’s science and technology research at the Royal Society’s Summer Science Exhibition in London next month.

“Even a novice can use the device to move a 1 micron (1,000th of a millimetre) diameter glass sphere,” says Dr Dholakia.

Although simple to use, the tweezers can only manipulate very small objects but, fortunately, the biological world falls within its range.

A whole ‘optical tool bag’ is being developed by Dr Dholakia consisting of the tweezers and ‘optical scissors’ which can cut through molecules like DNA. With colleagues led by Dr Peter Bryant in the School of Biology, the ‘optical tool kit’ is being used to investigate how DNA is damaged.

“We can grab a chromosome,” explains Dr Dholakia. “And cut out an area of it where we think there is damage or a genetic defect and investigate the cause of the damage.”

The results could help understand how damaged DNA can cause diseases such as cancer. Dr Dholakia believes that the technology shows that lasers are not just tools for physicists but have a wide application across all science.

Dr Dholakia’s input into the event coincides with that of Dr David Logan and Dr Alyson Tobin from the School of Biology who are undertaking research into Mitochondria, the powerhouses of living cells.

They produce the energy that the rest of the cell needs to function and, without them, a cell cannot survive. Despite this crucial role, knowledge of how the behaviour of mitochondria is controlled by the cell is a major unknown in biology.

Whilst at Oxford University, Dr Logan developed a technology to tag mitochondria in a common weed, Arabidopsis, with a green fluorescent protein found naturally in jellyfish.

“We are now able to investigate the genes controlling the shape, size and number of mitochondria in a plant cell using a conventional fluorescent microscope,” says Dr Logan.

Visitors to the Royal Society’s Summer Science Exhibition will be able to see the fluorescent mitochondria themselves – previously only a possibility if you had an electron microscope to hand. “Even biologists will be amazed,¿ believes Dr Logan.

A better understanding of how plant genes”control mitochondria could lead to improved crops, as a better understanding of how plants produce energy should enable the design of more efficient varieties.

The two teams from St Andrews are among 20 selected from the whole of the UK science community to take part in the exhibition.

The Royal Society’s Summer Science Exhibition takes place from 2-4 July 2002 at the Royal Society, 6- 9 Carlton House Terrace, London SW1Y 5AG. Free to enter, the exhibition is open from 10am to 4.30pm each day, except Tuesday when it opens slightly later at 12.30pm. Anyone interested in attending can find out more by calling 020 7451 2574 or visiting



Photographs relating to the research on show is available for some exhibits. A press preview of the exhibition will be held at the event at 10.30am on 2 July 2002.

For further information, contact:

Liz Brodie/Bob Ward/Soccy Ponsford Press and Public Relations The Royal Society, London Tel: 020 7451 2568/2516/2508 E:mail: [email protected]


Issued by Beattie Media on behalf of the University of St Andrews For more information please contact Gayle Cook on 01334 467227, 07900 050 103 or email [email protected] Ref: royalsoc/standrews/chg/24june2002

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