The adsorption of polymers at surfaces is of important interest in technology. Processes of scientific and industrial importance such as adhesion, lubrication, colloid stabilization or flocculation often depend on polymer adsorption on surfaces. Adsorption of DNA on surfaces is of importance as most DNA interactions with other macromolecules involve the matching of different surfaces. The interaction of DNA with inorganic materials may helps in the possible explanation of the prebiotic stages of evolution of life. In addition DNA nanotechnolgoy requires a strong control of the adsorption of DNA on surfaces in order to prepare and characterize constructions and devices that can take advantages of the physical and chemical properties of this molecule.

Although both mica and graphite are the prefer substrate for STM, graphite was found not a good substrate for DNA spreading and adsorption. Divalent ions like Mg are now commonly used to mediate the adsorption of DNA on freshly cleaved mica. A rough guideline that a mM conc. of Mg ion in solution with a nM conc. DNA in a low ionic-strength buffer at physiological pH is enough to efficiently adsorb DNA onto a freshly-cleaved strip of mica in a few minutes. The adsorption depends mainly on electrostatic interactions between the charged mica surface and the DNA phosphate backbone. Kinetics studies show that the adsorption is diffusion control, and it is suggested that once DNA adsorbed onto the mica, it never desorb.

In optimized conditions or relatively weak adsorption, DNA molecules would be able to diffuse on the surface in 2D allowing it to sample their conformational space. In the other extreme, DNA get trapped into the conformation that they were in when they first in contact with the mica surface.