Past studies of DNA-surfactant aggregates involving UV-spectroscopy and gel electrophoresis show that when 20 to 100 base-length oligonucleotides interact with the surfactant CTAB in specific ratios of surfactant to oligonucleotide base, they form aggregates. The interaction between the oligonucleotide and surfactant molecule appears to involve both the hydrophilic head and the hydrophobic tail of CTAB. We characterized these aggregates using an atomic force microscope (AFM) by drying DNA-CTAB solutions on mica and silicon, reconstituting the dried aggregates in buffer and imaging them in fluid. Topographical data was collected that showed consistent, almost hexagonal, regular patterns of aggregates on the surface, and we studied the surface properties of the aggregates using force spectroscopy with functionalized AFM tips. The spring constants of the aggregates and information on the adhesion forces between the derivatized tips and the aggregate surfaces were obtained. Preliminary results show that tips functionalized with 1-dodecanethiol were found to have a lower adhesion to the aggregate surface than tips functionalized with mercaptoundecanoic acid implying that the surface of the aggregate is also hydrophilic.