Researchers at the University of Rochester have developed a novel optical technique that permits rapid analysis of single human immune cells using only light. Andrew Berger, associate professor of optics and his graduate student Zachary Smith integrated Raman and angular-scattering microscopy into a single system, which they call IRAM. This is the first time clear differences between two types of immune cells have been seen using a microscopy system that gathers chemical and structural information by combining two previously distinct optical techniques, according to Berger. “Conceptually it’s pretty straightforward – you shine a specified wavelength of light onto your sample and you get back a large number of peaks spread out like a rainbow,” says Berger. “The peaks tell you how the molecules you’re studying vibrate and together the vibrations give you the chemical information.” Until now scientists have not had a non-invasive way to see how human cells, like T cells or cancer cells, activate individually and evolve over time.