Now, tiny fishing reel to untangle DNA strands with laser beams

London, July 14 : A team at Kyoto University, Japan has designed the world's smallest fishing reel to store, without any damage, long DNA strands that have a tendency to become tangled.

Kyohei Terao and his colleagues have designed this microdevice to enable geneticists more precisely locate specific genes and identify genetic disorders.

The researchers have developed minuscule hooks and bobbins that mimic the way a fishing reel winds line onto a spool as a safer way to manipulate DNA.

Made from a polymer called SU-8 photoresist that doesn't bind to and damage the DNA, these microdevices are manipulated by using a tightly focused laser beam as a pair of optical tweezers.

In order to detach the strands, the scientists firstly used Z-shaped microhooks - which are barbed -to latch onto the DNA strand. Now it was possible to easily untangle the centimetre-long strands for genetic tests just by moving the laser beam. Then the researchers can utilise multiple hooks to stretch out a strand of DNA for analysis.

Terao said that breakages in the DNA strands are less likely because the DNA isn't chemically modified before manipulation, and because the microhooks grab the middle of the molecules instead of the ends.

"The microhooks and bobbins were inspired by manipulation of thread using our fingers," The New Scientist quoted Terao, as saying.

"This is an impressive piece of microengineering. However, relevant applications are still pretty far down the road - there will be a major challenge for applying this to complex genomes such as those of vertebrates and man," said Edwin Cuppen at the Netherlands Institute for Developmental Biology in Utrecht.

He even mentioned that some existing techniques can already stretch out single DNA molecules for genetic studies.

"David Schwartz has developed an optical mapping technology, where long single DNA molecules are stretched in microchannels and can be subsequently manipulated," he said.

ANI