Author/Authors :
Daniel M. Czajkowsky، نويسنده , , Daniel M. and Allen، نويسنده , , Michael J. and Elings، نويسنده , , Virgil and Shao، نويسنده , , Zhifeng، نويسنده ,
Abstract :
Tapping mode atomic force microscopy operated in the phase shift mode is used to directly visualize the surface charge on biological macromolecules under solution. A simple theory is presented which is qualitatively consistent with experimental observations, although a more complicated theoretical analysis is required for a quantitative comparison.