A new twist on a technique called cryo-electron tomography offers a closer-than-ever look inside a human skin cell: it generates a 3-D image with resolution fine enough to distinguish the structures of proteins.

The new method, which involves freezing a cell and slicing it into thin sections, will allow scientists to probe how proteins organize and interact deep within a cell without disturbing them from their native states. The images have a resolution of three to four nanometers, allowing scientists to discern the structures of individual proteins.