text: One unique property of xDNA is its inherent fluorescence. Natural bases can be bound directly to fluorophores for use in microarrays, in situ hybridization, and polymorphism analysis. However, these fluorescent natural bases often fail as a result of self-quenching, which diminishes their fluorescent intensity and reduces their applicability as visual DNA tags. The pi interactions between the rings in x-nucleobases result in an inherent fluorescence in the violet-blue range, with a Stokes shift between 50 and 80 nm. They also have a quantum yield in the range of 0.3–0.6. xC has the greatest fluorescent emission.