Cells regulate their functions by adding or subtracting phosphates from proteins. If scientists could study the phosphorylation process in detail, in individual mammalian cells over time, understanding and treating diseases would be greatly aided. Formerly this was impossible without damaging the cells or interfering with the process itself, but Berkeley Lab scientists and their colleagues have now achieved the goal using the Advanced Light Source’s bright infrared beams and a technique called Fourier transform spectromicroscopy.