High-res microscope

Biomedical engineers in the US have developed a microscope that can image proteins inside live cells with double the resolution of fluorescence microscopy using structured illumination.

The microscope was developed by an academic team from the University of Georgia in Athens (UGA) and the University of California in San Francisco (UCSF).

The development could help scientists learn more about cell behaviour and study mechanisms important for human disease.

The fluorescence microscope has allowed a generation of scientists to study the properties of proteins inside cells. Yet as human capacity for discovery has made its way down to the nanoscale, fluorescence microscopy has struggled to keep up.

The laws of physics have limited the resolution of fluorescence microscopy, whereby a fluorescent marker is used to distinguish specific proteins, to about 200nm. At this resolution significant detail is lost about the activity within a cell.

‘Our understanding of what is going on inside cells and our ability to manipulate them has advanced so much that it has become more and more important to see them at a better resolution,’ said Peter Kner, a University of Georgia biomedical engineer who helped build the new microscope.

This work follows a decade of research building on the nearly 50-year history of fluorescence microscopy. The technology has been a multi-disciplinary springboard of optical engineering, chemistry and biology. All disciplines have contributed to visualising fluorescent dyes attached to proteins and advancing scientists understanding of cellular activity.

The importance of fluorescence microscopy was recently recognised with the 2008 Nobel Prize for Chemistry that was awarded for the development of the green fluorescent protein (GFP), which has played a crucial role in the identification and understanding of proteins.

‘What we’ve done is develop a much faster system that allows you to look at live cells expressing GFP, which is a very powerful tool for labelling inside the cell,’ Kner explained.

‘It would be difficult to overstate the importance of bio-imaging to ongoing research in human health,’ said Dale Threadgill, director of the faculty of engineers at the University of Georgia in Athens. ‘The ability to shine a light on the leading edge of scientific discovery will define the route to entirely new regimens of health management at the intersections of science and engineering, and Dr Kner has joined a distinguished cadre at UGA to continue working at that interface.’