Imaging in different modes (Phase mode in particular) allow to probe the elasticity of the surface cells, nanoparticles.

 Fig 10  Fig 11
3D AFM image of polymer micelle in height (left) and phase (right) modes. Height mode shows the uniform surface of the particles but  phase mode clearly  reveals the areas of different softness on the surface of the micelle.  The sample was provided by Dr. T. Bronich, University of Nebraska Medical Center, USA.

protein-polymer nanoparticles

AFM image of protein-polymer nanoparticles (unpublished data) in height (left) amplitude (middle) and phase mode (right). All 3 AFM modes clearly show the more rigid core (cross-linked complexes) inside the softer (polyethylene glycol) shell of the particles. Sample was provided by Dr. Devika S Manickam, Prof. Alexander V Kabanov’s group at the Center of Drug Delivery and Nanomedicine, University of Nebraska Medical Center, USA.