Current Affiliation: University of California, Berkeley
Ph.D. alma mater: California Institute of Technology
Role model: Richard Feynman. “A perfect example of how one can be both adventurous and down-to-earth, theoretical and practical, a great researcher and a great teacher.”
In a world without chemistry, I would be: “a musician or a computer programmer.”
Codename: Image Interrogator
On his first day as a graduate student in Jim Heath’s group at Caltech, Ke Xu was handed a paper that was about to be submitted for publication. “I got a long note the next morning saying the theory part was not quite right,” Heath remembers. At first, Heath thought, “What chutzpah!” But then he realized that Xu was right.
Xu’s name was added to the paper and the chemist has been on the fast track ever since. In the three years since starting his own lab at the University of California, Berkeley, he has already made important contributions to the field of superresolution microscopy, advances that allow him to generate Technicolor images of the structural details of cells.
One of Xu’s contributions was to combine fluorescence spectroscopy with superresolution microscopy so that researchers can distinguish between assorted components in a cell at the same time. To use the technique, Xu tags the components with dyes or proteins that have slightly different fluorescence spectra. That allows him to see multiple components in a cell simultaneously at a previously unachievable resolution. “We can easily do multicolor imaging for four colors at the same time,” Xu says.
In another contribution to the field, Xu’s group figured out a way to do superresolution fluorescence imaging and electron microscopy on the exact same cells without drying them. Previously, researchers would have had to go through a difficult, error-prone dehydration process to make samples compatible with electron microscopy before they could capture cellular details with both methods, which can make images difficult to correlate and conclusions tough to nail down.
Xu plans to use the methods he’s developed to probe the internal structure and dynamics of cells at nanometer resolution. The combination should help him understand the inner workings of cells.
“Since he’s gotten to Berkeley, he’s done two beautiful experiments that have pushed the field forward,” Heath says. “And this is not an empty field. This is a crowded field.”
Research at a glance
Three key papers:
“Ultrahigh-Throughput Single-Molecule Spectroscopy and Spectrally Resolved Super-Resolution Microscopy” (Nat. Meth. 2015, DOI: 10.1038/nmeth.3528)
“Graphene-Enabled Electron Microscopy and Correlated Super-Resolution Microscopy of Wet Cells” (Nat. Commun. 2015, DOI: 10.1038/ncomms838)
“Actin, Spectrin and Associated Proteins Form a Periodic Cytoskeletal Structure in Axons” (Science 2012, DOI: 10.1126/science.1232251)
They might be young scientists, but our Talented 12 have already traveled far and wide.
Watch Xu talk about his research during a special Aug. 22 Talented 12 symposium held at the American Chemical Society national meeting in Philadelphia.
Story in C&EN about Xu’s research:
“Covering Up for a Clear View”
CORRECTION: On Aug. 29, 2016, this profile was updated to correct the resolution at which Ke Xu’s combined fluorescence spectroscopy/superresolution microscopy technique works: It can distinguish cell components 10 nm apart or more. And it was updated to correct a statement about how researchers previously combined electron microscopy and superresolution fluorescence imaging: They could use both techniques on a single-cell sample, but the sample had to go through a difficult, error-prone dehydration process.