August 13, 2008
Fluorescent Genetic Barcodes
By Luntz, Stephen
The capacity to track gene expression has been one of the biotechnology revolution's driving forces, so a technology that gives researchers more accuracy and sensitivity has the potential to lead to even more rapid progress. Dr Krassen Dimitrov of the Australasian Institute of Bioengineering and Nanotechnology at the University of Queensland has created what he calls "nanostrings". These are fluorescent pieces of nucleic acid that act like barcodes, binding to RNA molecules and providing researchers with an easy-to- read measure of the presence of biomolecules.The technology has several advantages over the microarrays used currently. It provides a digital count, recording the exact number of RNA molecules, rather than an analogue result, where the correspondence between luminosity and the amount of molecules breaks down at high and low values. "Because this system can count the exact number of biomolecules present we can get an extremely accurate and sensitive picture of gene expression at a particular point in time," Dimitrov says.
Another advantage is that the nanostrings do not require the conversion of RNA to DNA, followed by enzyme conversion to fluorescing DNA. "Enzymes are finicky and don't work if the conditions are dirty," Dimitrov says.
"The nanostringis an important technological development in both clinical and research settings. We will be able to more accurately detect molecules associated with particular diseases, and in the research arena we will be able to identify new molecules associated with diseases and trace these back to the genes responsible."
The nanostrings are being commercialised by a company that Dimitrov founded for the purpose in 2003. Technical obstacles prevented the nanostrings from reaching the market until now. Although patents were awarded years ago, business interests were not keen for the technology to be publicised until a product was ready for market. The splash was significant, with the invention making the March cover of Nature Biotechnology.
Meanwhile Dimitrov is working on a new generation of nanostrings capable of emitting electronic signals rather than light, which he says will make them "easier to count and much smaller".
These fluorescent markers provide an exact record of the RNA molecules expressed.
Copyright Control Publications Pty Ltd Jul 2008
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