An injection of magnetic nanoparticles into your bloodstream could reveal precisely where harmful viruses are lurking reports New Scientist. The particles are coated with antibodies to a particular virus, so they will form clumps that should be visible on conventional body scans if that virus is present. The team working on the technology, from the Harvard Medical School's Center for Molecular Imaging Research in Charlestown, Massachusetts, have already managed to detect viruses in body fluids and tissue samples. They hope to be able to detect viruses in patients' bodies within a couple of years. Much of the technology has already been tested in humans, so the scientists are confident that it will be safe. Scans revealing where virus populations are - HIV, for example, tends to concentrate in the lymph nodes - could help doctors improve treatments. And a scan could reveal whether viruses used in gene therapy to ferry new DNA into patients have actually reached the parts of the body they are intended for - and in sufficient numbers to do any good (Journal of the American Chemical Society, DOI: 10.1021/ ja036409g). Full article here.