Solution scattering from biopolymers: advanced contrast-variation data analysis

New approaches to the interpretation of contrast-variation data from monodisperse systems using spherical harmonics are presented. A general method is given for evaluating the particle shape and internal structure and expressions for the scattering from the density fluctuations inside a particle with a known shape are derived. Further, the scattering from two-component particles is analyzed in terms of the positions and/or shapes of the components and the information content of the contrast-variation data is discussed. The methods can be used for advanced low-resolution structure analysis of various types of biopolymers in solution.