Experimental Method to Distinguish between a Solution and a Suspension

Dispersion of objects in a fluid phase can be classified as solutions (Gibbs free energy mixing, ?Gmix < 0) or suspensions (?Gmix > depending on their thermodynamic stability. Small tend to form solutions, larger ones suspensions, e.g., molecules versus micrometer-sized colloids. Proteins and nanomaterials fall between these two size regimes. The long-standing issue whether proteins nanoparticles are dissolved suspended remains an important research question. Here, simple, versatile, experimentally robust method, based sedimentation equilibrium analytical ultracentrifugation (SE-AUC), which determine proteins, nanoparticles, polymers is presented. SE-AUC determines the osmotic pressure profile for dispersion. Such (equilibrium one-phase systems) independent initial operating conditions. opposite true that nonequilibrium two-phase systems. This study proves bovine serum albumin lysozyme while ferritin apoferritin suspensions.