ABSTRACT
In this chapter, I will give a broad overview of recent work on the equation of state of DNA in aqueous monovalent salt solutions. The picture that I will develop shows that at non-negligible monovalent salt concentrations the direct electrostatic interactions between DNA molecules are almost always masked by the thermal conformational uctuations of the DNA chains. These thermal uctuations act to boost the magnitude as well as the spatial range of the electrostatic interactions. This renormalisation of the bare electrostatic interactions is a salient feature of dense systems composed of exible polyelectrolyte molecules.
