New 'barcode' technique to study gene activity

Researchers at the University of Queensland, Australia, have developed a technique to digitally barcode gene activity, handing scientists a uniquely powerful tool for the prediction and prevention of disease.

The fluorescent 'nano-string' is simply added to blood where it binds to a molecule of the researchers' choice. The sample is then scanned to assess whether the molecule is present and, if so, how many copies: in effect, a molecular stock-take. The combination of simplicity, power, and reproducibility is unrivalled in current tools for analysing gene activity, or gene 'expression' levels.

Published in Nature Biotechnology, researchers tagged up to 1000 different molecules in a single assay, whilst retaining accuracy comparable to conventional methods such as real time-PCR (polymerase chain reaction) - a single molecule per cell can be detected.

'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', said team leader Dr Krassen Dimitrov.

The scientific process behind the nanostring lacks a DNA amplification step common to existing techniques, removing bias and so giving a more accurate result. Error is further reduced by digital detection of the nanostring's barcode - a feature unique to nanostring technology - removing the variation introduced with conventional analogue scanning techniques.

'The nanostring is 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', said Dr Dimitrov. The team are now looking to expand the range of molecules the nanostring can detect whilst reducing cost and improving efficiency.