Beside the predominately found 8-(arylamino)-2'-dG, 8-(acetylarylamino) damages within DNA- strands may also play an important role in the induction of chemical carcinogenesis. A synthesis pathway leading to these 8-( acetylarylamino)-dG adducts using different aromatic amines has been optimized. The 8-modified dGs were converted into the corresponding phosphoramidites and site-specifically incorpo-rated into different oligonucleotides leading to DNA strands. Lesion-bearing hybrids of these damaged DNA-strands with complementary oligonucleotides were used to study their melting properties and their circular dichroism spectra. It was shown that no EcoRI restriction took place with the damage inside the cleavage site. Finally, three different DNA polymerases were used for primer extension studies.