The kaleidoscopic ball above is more—and less—than meets the eye. This vivid terrain is actually a color-coded Zika virus, millions of which could fit in the period that ends this sentence.
We can see the virus here thanks to cryo-electron microscopy (cryo-EM), an extremely cool imaging technique that lets scientists visualize molecules, making it easier than ever to study life’s cellular machinery.
Cryo-EM works by firing an electron beam at a flash-frozen film of water containing copies of a given molecule. This “exposure” yields many 2-D images of the molecules at different angles, which algorithms then merge into one 3-D model. At first cryo-EM rendered molecules as vague lumps, so some dismissed it as “blobology” compared with x-ray crystallography, a less versatile high-resolution imaging technique. But in 2013 cryo-EM achieved atomic resolution for the first time.