van Holde - Weischet Tutorial

Introduction

In recent years analytical ultracentrifugation (AUC) has gained considerable recognition as an important technique employed in biochemical laboratories for the physical characterization of biological macromolecules and macromolecular assemblies in solution. With the advent of the Beckman Optima XL-A and XL-I analytical ultracentrifuges, accuracy, resolution, reliability and reproducibility of experimental results have increased significantly.

This increase in quality of experimental data has motivated many researchers to tackle more complex biological systems which often involve multiple components and interactions between them. When dealing with systems that contain more than one solute it is important that one is able to differentiate between these components and is able to identify them correctly.

Oftentimes, the researcher deals with systems of unknown composition and the number of the individual components and their properties are not known. In such cases, data from sedimentation velocity experiments can be used successfully to identify heterogeneity in molecular weight or frictional properties by analyzing this data with the van Holde - Weischet method.