Single excitation three color folded DNA probe for SNP typing

A single fluorophore based multi-color emission probing system has been developed in the current work. dA^py was used as the fluorophore, which was incorporated at the end of folded oligonucleotide with increasing number. Depending on the number of dA^py three different color emissions were observed, viz. blue, green and red. These interesting color patterns were further used for the SNP typing of DNA. Every folded oligonucleotide with different number of dA^pys could discriminate the full matched target sequence from one base mismatched and two base mismatched sequences. Furthermore, this probing system has a simple structure and also exhibited large Stokes shifted signal for discriminating the target DNA.