Second harmonic generation (SHG) image of starch granules of a potato slice. The main constituent of the starch granules is highly ordered semicrystalline amylopectin, which renders them a noncentrosymmetric structure ideal for label-free SHG imaging. The forward and backward scattering SHG signal obtained from the radial distribution of the amylopectin is depicted by the red and green, respectively. The backward signal (green)from the amylopectin supramolecular assembly is more intense at the outer layers of the granules while the forward signal (red) intensity is higher at the inner core. Image was taken with LSM 710.