DNA POLYMERASE STOP ASSAY FOR DETECTION OF G-QUADRUPLEXES

In this work we performed DNA polymerase stop assays while using template DNA derived from promoter regions of VEGF and c-Myc proto-oncogenes under variety of experimental conditions. Partial stopping of DNA synthesis along the template strand was observed in the presence of K+ ions due to formation of stable G-quadruplex structures. In contrast, Na+ ions alone were unable to stabilize G-quadruplexes to stop the reaction at their site. These data suggest that K+ and Na+ ions, which are both known to stabilize G-quadruplexes, do this in different manner or extent.