CHeprun 5 Determination of Macromolecular Homogeneity, Shape, and Interactions Using Sedimentation VelocitY Analytic al Ultraeentrifugati on

Since its inception by Svedberg and coworkers in the 1920s, the analytical ultracentrifuge has provided a powerful tool in biochemistry and molecular biology, with applications ranging from simple purity checks and particle shape determinations from sedimentation velocity, isolation and purification of macromolecules using density gradient techniques right through to the evaluation of mol wt and mol-wt distributions, thermodynamic second virial coefficients, and association constants using sedimentation equilibrium, without the need for calibration standards. By the 1960s, the familiar"Beckman Model E" had become commonplace in biochemical laboratories worldwide. With the advent of the "high-resolution" techniques of X-ray crystallography and nuclear magnetic resonance (NMR) for structural analysis and the relatively straightforward techniques of gel electrophoresis and gel permeation chromatography for purity and mol-wt analysis, the technique suffered a serious decline in popularity in biochemistry and molecular biology with the result that, by 1980, relatively few laboratories had this tacility. However, for both structural and mol-wt analysis, the technique is now undergoing a form of renaissance, culminating in the launch of the new Optima XLA