Spectrum of Light Scattered from Charged Macromolecules in Solution

Abstract

Many macromolecules of biological interest, when dissolved in water, acquire charges and these charges are shielded by an atmosphere of counterions. The effect of the ion atmosphere on the diffusion constants of the molecules and hence on the spectrum of scattered light from such a solution is investigated here using a simple model. It is found that the ionic atmosphere can have an important effect on the diffusion of the macromolecules and that measurement of the spectrum of scattered light may provide a way to measure the residual charge on the macromolecules.