A Scanner for Hereditary Defects (image) University of Zurich Caption The XPD scanner (green)is in close contact with a damaged point (red) on the DNA double helix. The damaged DNA strand lies in a deep pocket of the protein to enable a ferrous sensor (Fe) to come into contact with the damaged point, thereby halting the protein as it moves along the DNA. Credit Picture: UZH Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.