Imaging xanthan gum in air by ac “tapping” mode atomic force microscopy

Images of the bacterial polysaccharide xanthan gum have been obtained in air using an atomic force microscope operating in the ac “tapping” mode. Aqueous solutions of xanthan were deposited onto freshly cleaved mica and allowed to dry in air. Images have been obtained at high and low coverage of the substrate revealing both networks and individual molecules.