Session Z8 - Focus Session: Novel surface-based techniques for biomolecules and biomolecular thin films.
FOCUS session, Friday midday, March 26
510A, Palais des Congres
We have studied the dynamics of DNA chains on surface in order to attain a more detailed understanding of the mechanism of surface electrophoresis. We have measured the diffusion and mobility of DNA chains on hydrophilic silicon surface by using Laser Fluorescence Microscope. The result showed that the diffusion on surface was minimum, while it was much bigger in buffer and the mobility increased linearly with electric field within certain range. We also directly observed single chain motion of linear, circular and supercoiled DNA by CCD camera. The motion of different DNA chains we observed was consistent with changes in chain conformation due to surface attraction. Neutron reflectivity was also performed on DNA chain adsorption in an electric field, from which the loop size of adsorbed DNA chain can be determined. These data will be compared to a theoretical model of the individual chain motion on an attractive surface.
Supported by NSF-GARCIA center