Pre-Targeting (IMAGE) Helmholtz-Zentrum Dresden-Rossendorf Caption Tracking the tumor: PNA-antibodies detect initially the diseased cells (red) and accumulate at the tumor site. Afterwards the radioactively labeled probes (blue) selectively bind to them by specific base pairing. Modern imaging methods allow the scientists thus to visualize the tumor. Credit HZDR/Pfefferkorn Usage Restrictions Use only with with appropriate caption or credit. License Licensed content 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.