Generalization of the Radial Dilution Square Law in Ultracentrifugation

The classical square law of radial dilution, which relates the concentration of a single component to the boundary position in the ultracentrifuge cell, has been examined and found to be valid for a single component as well as for a multicomponent system even though the sedimentation rates are dependent on concentration. The square law has been generalized to give corrected concentrations without the necessity of determining boundary positions explicitly. A system of warped coordinates has been introduced to simplify this application of the square law. A special template and its use is described which incorporates both the warped coordinates and the baseline and which enables very rapid reading of areas from routine ultracentrifugal runs.