Single Nucleotide Polymorphism Detection Using a Biocompatible, Fluorogenic and DNA-Templated Reaction of Cyanine Dye Formation

Water-soluble Peptide Nucleic Acids (PNAs) functionalised with fluorogenic cyanine dye precursors (i.e. a Fisher's base aldehyde and a 2-methylene indolenine) are employed for detecting single-nucleotide polymorphism in vitro under near physiological conditions of salt and pH. This quick and versatile fluorogenic system has been designed so that fluorescence is formed only upon simultaneous hybridisation of both PNAs to a fully complementary DNA strand. The reaction yield increased up to around 10% upon addition of the DNA template, even in the presence of a large excess of Calf-Thymus competitor DNA.