Structurally Defined Ru(II) Metallointercalators for Real-Time Monitoring of DNA Amplification Reactions

The low cost and convenience of fluorescent DNA binding dyes make them widely used for real-time DNA analysis. Even though several dyes for real-time polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) assays are commercially available, most of them rely on organic parent molecules with an indefinite chemical structure, making it difficult to predict their behavior in nucleic acid amplification and to get the best performance. Herein, we demonstrate for the first time the use of the structurally defined dipyridophenazine complexes of ruthenium(II) for real-time monitoring of PCR and LAMP. These inorganic metallointercalators exhibit less inhibition on DNA amplification. They can quantify a range of initial template concentrations and provide the product melting curve to differentiate the unspecific amplification and even perform multiplex assays. These ruthenium(II) complexes have the advantages of the defined structure, nontoxicity, good stability, and facile synthesis, and they may act as excellent alternative DNA binding dyes with wide applications in the field of nucleic acid research.