Interaction of Malachite Green with Guanine‐Rich Single‐Stranded DNA: Preferential Binding to a G‐Quadruplex

Bound to be better: The formation of a strong complex between the chromophoric dye malachite green (MG, in green) and the G-quadruplex structure (represented in black) of the guanine-rich single-strand oligomer sequence d(G2T)13G results in a 100-fold enhancement of the fluorescence yield of MG. The existence of an intra- or interstrand G-quadruplex structure depends on the oligomer concentration and the ionic strength of the solution.