Probing the structure of water in living cells

Being the active matrix of life, water regulates or even governs a wide range of biological processes. Despite its fundamental importance, surprisingly little is known about the structure of intracellular water. Central questions are open: whether the hydrogen-bonded network of water inside living cells differs from that of bulk liquid water, and if so, what are the abundance, location and new structural features of such water? The lack of understanding is largely due to experimental difficulties to probe water structure in living cells. Herein we present a Raman micro-spectroscopy technique to uncover the composition, abundance and vibrational spectra of intracellular water in individual living cells. Our study not only opens up experimental possibilities of interrogating water structure in vivo but also provides fundamental insights into water in life.