Science: A laser built into a single cell may one day be used for light-based therapeutics, writes Jon Cartwright for Science. Physicists Malte Gather and Seok-Hyun Yun of Harvard Medical School used cells derived from a human kidney and added the DNA that codes for green fluorescent protein (GFP), then placed some of the cells producing GFP between two mirrors a single cell’s width apart. To lase, the GFP in the cells needed to be pumped with another laser, which sends pulses of blue light at about 1 nanojoule. The light bounced back and forth, amplifying the diffuse light from the GFP into a coherent green beam. Gather and Yun are interested in the therapeutic applications of their device. They also speculate that it might eventually help the backbone of optical communications shift to biotechnology.
The finding that the Saturnian moon may host layers of icy slush instead of a global ocean could change how planetary scientists think about other icy moons as well.
Modeling the shapes of tree branches, neurons, and blood vessels is a thorny problem, but researchers have just discovered that much of the math has already been done.
January 29, 2026 12:52 PM
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