Live-cell fluorescence imaging identifies bona fide reprogrammed cells.Fluorescence imaging could help resolve whether iPS cells have been properly programmed.Alamy The next tools for reprogramming cells to an embryonic-like state might just be a camera and a set of fluorescently tagged antibodies. Researchers imaged more than a million human cells in vitro as they changed from skin tissue cells, known as fibroblasts, into colonies of induced pluripotent stem (iPS) cells. As expected, many similar-looking colonies appeared, but only very few consisted of fully reprogrammed iPS cells. After assessing which were which, researchers led by Thorsten Schlaeger and George Daley of the...