Imagine spending your whole life seeing the world in black and white, and then seeing a vase of roses in full color for the first time. That’s kind of what it was like for the scientists who have taken the first multicolor images of cells using an electron microscope. Electron microscopes can magnify an object up to 10 million times, allowing researchers to peer into the inner workings of, say, a cell or a fly’s eye, but until now they’ve only been able to see in black and white. The new advance—13 years in the making—uses three different kinds of rare earth metals called lanthanides (think top row of that extra block below the periodic table) layered one-by-one over cells on a microscope slide. The microscope detects when each metal loses electrons and records each unique loss as an artificial color. So far, the researchers can only produce two colors—red and green, they report online today in Cell Chemical Biology. Still, the ability to use color creates stark contrasts that grayscale images simply can’t accomplish. The team could see a string of proteins squeezing through a cell membrane (pictured) in more detail than scientists ever had before, for example. With a few more tweaks and added metal ions, researchers hope to add more colors to the mix and improve the images’ resolution.
Correction, 29 November, 5:40 p.m.: An earlier version of this article incorrectly stated the researchers could produce three colors. It also stated the advancement took 15 years. The article has been corrected.