Analytical Ultracentrifugation

Analytical Ultracentrifugation designates a solution-phase biophysical technique characterising macromolecular properties including molecular weight, size, shape, hydrodynamic parameters, and association equilibria by monitoring sedimentation behaviour under high centrifugal fields using optical detection systems. This label-free method provides absolute physical measurements without requiring column matrices or immobilisation.

The biopharmaceutical industry employs analytical ultracentrifugation for comprehensive characterisation of protein therapeutics, particularly evaluating aggregation state, self-association equilibria, and molecular weight distribution in solution-phase conditions resembling physiological environments. Sedimentation velocity experiments determine size distribution and hydrodynamic properties. Sedimentation equilibrium measures thermodynamic association constants and molecular weights. Applications include characterising monoclonal antibody aggregates, evaluating bispecific antibody integrity, and assessing nanoparticle properties. Regulatory submissions for biologic characterisation often include analytical ultracentrifugation data as part of higher-order structure packages. As biologic complexity grows, analytical ultracentrifugation continues providing definitive solution-phase characterisation complementing other analytical techniques.