Oligo-desoxyribonuleic acids (ODNs) having a sequence of 5'-TCC ATG ACG TTC-3' were modified at the 5' end by introduction of an amine group via a C6-amino linker. After subsequent reaction of the amine group with N-methacryloyloxysuccinimide, polymerizable ODNs were obtained. Free radical homopolymerization results in the formation of comb polymers, which possess an ODN side-chain at each repeating unit of the main chain. Mainly due to steric repulsion, the main chain has to adopt a semi-flexible wormlike shape instead of the otherwise preferred coiled structure. This leads to the formation of cylindrical poly(oligo-DNA) molecules. Characterization by static and dynamic light scattering of the poly(oligo-DNA) in aqueous solution gave a radius of gyration R-g,R-app = 67.8 nm, a hydrodynamic radius R-h,R-app = 44.6 nm, and a characteristic ratio of rho = R-g/R-h = 1.52, indicating the cylindrical shape in solution. In addition, the cylindrical poly(oligo-DNA) molecules were adsorbed onto mica and visualized by atomic force microscopy.