Stanford researchers have combined two microscopy techniques to create a one-of-a-kind instrument that can show cell structures interacting in real time at an unprecedented 120-nanometer resolution—the highest achieved without the use of fluorescent labels. This new “label-free” technology, called Interferometric Image Scanning Microscopy, or iISM, will allow scientists to observe cellular structures in their wider context, including their responses to intrusions, such as pathogens or drugs.