van Holde - Weischet Tutorial

Extrapolation Plot

The extrapolation makes it possible to separate the diffusion information contained in the apparent sedimentation coefficients from the sedimentation properties of the sample. In this plot, corresponding apparent sedimentation coefficients are extrapolated in a global linear fit to infinite time (zero on the inverse scale), where the intercepts mark the diffusion corrected S-values.

Figure 5: Shown above is a van Holde - Weischet extrapolation plot of sedimentation velocity data of a 2-component experimental system. In this plot, 10 scans have been analyzed with 20 equally spaced boundary fractions. For clarity, only a subset of the scans and divisions are shown in this example. A complete analysis is shown in the distribution plot on the next page.