Sedimentation is a classic method of biochemistry that provides first‐principle hydrodynamic and thermodynamic information about the purity, size, shape, molar mass, association energy, association stoichiometry and thermodynamic nonideality of molecules in solution. The fundamental measurement in sedimentation is the concentration as a function of radial position. Any of the three optical systems provides the necessary concentration profiles, making sedimentation a versatile tool for analysing biological solutions. There are two distinct sedimentation methods: sedimentation velocity and sedimentation equilibrium. Data analysis from either method uses computer programs developed around fundamental equations. Velocity sedimentation is used to check for impurities and also to characterise molecular interactions. Equilibrium sedimentation is not used as widely, but it is used to provide first‐principle insights into intermolecular interactions such as macromolecular binding and thermodynamic nonideality.
Molecular, Cellular and Biomedical Sciences
Encyclopedia of Life Sciences
Digital Object Identifier (DOI)
Laue, T.M. (2010) "Sedimentation" in Encyclopedia of Life Sciences, www.els.net