Real-time visualization of intracellular hydrodynamics in single living cells

Intracellular water concentrations in single living cells were visualized b y nonlinear coherent anti-Stokes Raman scattering (CARS) microscopy, In com bination with isotopic exchange measurements, CARS microscopy allowed the r eal-time observation of transient intracellular hydrodynamics at a high spa tial resolution. Studies of the hydrodynamics in the microorganism Dictyost elium discoideum indicated the presence of a microscopic region near the pl asma membrane where the mobility of water molecules is severely restricted. Modeling the transient hydrodynamics eventuated in the determination of ce ll-specific cytosolic diffusion and plasma membrane permeability constants. Our experiments demonstrate that CARS microscopy offers an invaluable tool for probing single-cell water dynamics.