Beaming beetles

Laser or fluorescence microscopes are widely used to study properties of organic or inorganic substances.

The laser makes a specimen emit light, either because the specimen does so naturally or because it has been injected with fluorescent dye.

The trouble is that such dyes, when excited by laser light, generate toxic chemicals that kill living cells.

Now there may be a solution to that problem, thanks to John Lupton, an associate professor of physics, and his colleagues at the University of Utah.

Lupton's idea is a variation of fluorescence microscopy, but involves using an infrared laser to excite clusters of silver nanoparticles placed below the sample being studied.

The particles then form hotspots, which act as beacons, shooting intensely focused white light upward through the overlying sample.