Tracking molecules at video rate
A novel type of biomedical imaging, made possible by new advances in microscopy from scientists at Harvard University, is so fast and sensitive it can capture “video” of blood cells squeezing through capillaries. Researchers led by Harvard’s Brian G. Saar, Christian W. Freudiger, and X. Sunney Xie describe the work this week (Dec. 2) in the journal Science. The new technique, based on stimulated Raman scattering (SRS), makes a complementary partner to MRI, widely used to capture static images of organs and tumors. For the first time, SRS microscopy makes possible label-free chemical movies, with streaming footage at the subcellular level, catching video of proteins, lipids, and water within cells. “When we started this project 11 years ago, we never imagined we’d have an amazing result like this,” says Xie, professor of chemistry and chemical biology at Harvard. “It took MRI more than 30 years to reach patients, but we’re already looking forward...