Detection of C:C mismatch base pair by fluorescence spectral change upon addition of silver (I) cation: Toward the efficient analyses of single nucleotide polymorphism

We have already found that silver (I) cation specifically binds to C:C mismatch base pair in heteroduplex, which increases the melting temperature of heteroduplex involving C:C mismatch base pair by about 4 degrees C. This result shows that addition of the metal cation is a promising strategy for the mismatch base pair detection in heteroduplex, but UV melting to determine the melting temperature is time-consuming. In the present study, to develop a more convenient way for the mismatch base pair detection, we examined the fluorescence spectral change of fluorescent-labelled duplex upon addition of the metal cation. Addition of silver (I) cation to the heteroduplex involving the C:C mismatch base pair significantly changed the fluorescence intensity, but no significant change in the fluorescence intensity was observed for the duplexes involving other base pairs. Our results certainly support the idea that the fluorescence spectral change upon the addition of the metal cation could be a convenient strategy for the mismatch base pair detection by the heteroduplex analysis, and may eventually lead to progress in SNP genotyping.