In principle, the entire dataset can be evaluated globally, and efforts are underway to incorporate such routine into the Ultrascan evaluation software package (Demeler 2005). However, even then we are confronted with a confounded polydispersity of both optical and colloidal/hydrodynamic properties. In the left side of Fig. 2, the assumed core-shell structure of a β-carotene microparticle is shown (Auweter et al. 1999). Such a complex hybrid particle exhibits several levels of polydispersity, which impact the distribution of sedimentation coefficients observed in an AUC. They are for example:diameter of the inner core;
chemical composition, esp. oil content, of the inner core;
concentration of the adsorbed protection colloid (gelatin);
degree of swelling of the gelatin.