If it works in the macroworld, why not in the nanoworld?Researchers at Georgia Institute of Technology, at Emory University and at Georgia State University, all in Atlanta, were looking for a way to differentiate one nanosize probe from another in a busy field that could contain thousands of the tiny lights.Nanoparticles as they appear in the presence of a cancer gene sequence. Courtesy of Georgia Institute of Technology and Emory University.A software program already in use by astronomers allows them to pinpoint and analyze light from a single twinkling star, even if it is located in a dense cluster of other stars. Under the microscope, the brightly colored nanoprobes bear a striking resemblance to a starry night. The investigators applied the software to their miniature astrophysical display and discovered that it works. As reported in the March 4 issue of PNAS, they found that the software provides precise images of single molecules tagged with nanoprobes. Such images could enable researchers to garner more information about a molecule’s behavior and characteristics, such as how it binds in a gene sequence.The software was tried on color-coded nanoparticles that were applied to DNA molecules. The various colors targeted different sites on the molecule, only nanometers apart. The software detected and identified individual molecules. Lead researchers May D. Wang of Georgia Tech and Shuming Nie of Emory used the astrophysical photometry software called DAOPHOT to locate color-coded nanoparticle probes. The software’s algorithms enable millions of nanoparticle pairs to be processed every minute.The researchers believe that the approach has the potential to deliver high-speed detection in large sample volumes.