Interaction of methylene blue with DNA. A polarographic study

The binding of Methylene Blue to DNA was investigated through the polarographic diffusion current due to the Methylene Blue cation in DNA solutions under various conditions. Increased salt concentration reduced the binding, Mg2+ more than K+. Temperature from 25 to 55° had little effect, but increasing proportions of ethanol and acetone in the solutions reduced the binding markedly. The results suggest the participation of hydrophobic bonding in the Methylene Blue + DNA interaction.