IDENTIFICATION OF DNA-ADDUCTS AT SPECIFIC LOCATIONS BY SEQUENCING TECHNIQUES

1. A simple procedure for the accurate identification of the positions of adduct formation when viral M13mp18 single stranded DNA is treated with chloroacetaldehyde (CAA) is presented. 2. The normal dideoxy seq uencing reaction protocol was employed except no dideoxy nucleotides w ere used to cause chain termination. 3. Instead, the CAA adducted base s of the template DNA act as points of polymerase fall off causing the appearance of bands of DNA sequencing gel autoradiographs marking loc ations where adduct formation may have occurred.