Particles on DNA
Left: Height image of network of nanostructured calcium phosphate particles (white areas) interconnected by DNA (interconnecting lines), 20 µm scan. Right: Phase image showing lighter regions where there is a greater attraction between the tip and sample. In contrast, the DNA strands appear darker indicating a more repulsive interaction between the tip and sample, 20 µm scan.
Sample courtesy of P. Kumta, Carnegie Mellon University.