ANTI-ROS-DNA MONOCLONAL-ANTIBODY AS MOLECULAR PROBE FOR OXIDATIVE DNA-DAMAGE

Modification of 400 bp (approximate size) calf thymus DNA with (OH)-O- . radical resulted in lowered Tm, modification of thymine (58.3%), gua nine (20%) and single strand breaks. Monoclonal antibodies (mAb) gener ated against ROS-DNA were of IgG1 subclass. The mAb showed strong bind ing to ROS-DNA and ROS-modified bases and polymers, in particular, of thymine. The mAb, therefore, preferentially recognizes ROS-modified ep itopes on nucleic acids. Distinct binding to DNA isolated from aged, b ut not from normal humans by the monoclonal antibdy was observed. The antibody effectively recognized oxidative lesions in DNA from cancer p atients. These studies demonstrate the potential application of the mA b as an immunochemical probe to detect oxidative DNA lesions.