University of California, San Francisco and Ludwig Maximilians University researchers are using a new technique called 3-D structured-illumination microscopy to view living cells with 100 nanometers resolution.

The new microscope illuminates cells with interference patterns. When a fine cellular structure reflects this light, it changes the pattern slightly. The microscope collects it, then software interprets the changes and creates an image.

The inner workings of living cells have previously been impossible to resolve with optical microscopes, which are limited to a resolution of about half the wavelength of visible light, around 200 nanometers. Electron microscopy has the resolution, but can only be used on dead cells.