Top 5 Features Of Analytical Laboratory Centrifuge

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The analytical ultracentrifuge is still the most versatile, rigorous and accurate means for determining the molecular weight and the hydrodynamic and thermodynamic properties of a protein or other macromolecule. All terms in the equations describing sedimentation behavior are experimentally determinable.

Described below are some of the fundamental applications of the analytical laboratory centrifuge:

Examination of Sample Purity

The determination of average molecular weights by sedimentation equilibrium, coupled with a careful check on the total amount ofmass measured compared to what was put into the cell, can providesensitive and rigorous assessment of both large and small contaminants, aswell as allowing the quantitation of the size distributions in polydispersesamples. Because the sample is examined in freesolution and in a defined solvent, sedimentation methods allow analysis ofpurity, integrity of native structure and degree of aggregation uncomplicated ...
... by interactions of the macromolecules with gel matrix or support.

Molecular Weight Determination

The analytical ultracentrifuge is unsurpassed for the direct measurement ofmolecular weights of solutes in the native state and as they exist insolution, without having to rely on calibration and without having to makeassumptions concerning shape. The method is applicable to proteins, nucleic acids, carbohydrates—indeed any substance whose absorbance differs from that of the solvent.

Analysis of Associating Systems

Sedimentation analysis is even more valuable in studies of the changes inmolecular weight when molecules associate to form more complexstructures. Most biological functions depend on interactions betweenmacromolecules. While electrophoresis in gels containing SDS can provideinformation on the components and their relative stoichiometry in acomplex, sedimentation equilibrium provides the means of determining themolecular weight of the complex as it exists in solution, and independentof the shape of the particle.

Sedimentation and Diffusion Coefficients

Sedimentation velocityexperiments in the analytical ultracentrifuge provide sedimentation anddiffusion coefficients that contain information concerning the size andshape of macromolecules and the interactions between them. Sedimentation coefficients are particularly useful for monitoring changes in conformation in proteins and in nucleic acids. Bending in nucleic acids induced byprotein binding may also be amenable to study by difference sedimentation.

Ligand Binding

Absorbance optics is particularly well suited to studies of ligand binding,because of the ability to distinguish between ligand and acceptor. Analysis can be made simply with sedimentation velocity methodswhen the ligand and acceptor differ greatly in sedimentation coefficient,such as with cell separation. Provided there are significant changes in sedimentationcoefficient on binding, sedimentation velocity may also be used to studyinteractions between molecules of similar size.

Centrifugation of bloodand other samples is the best or the only method ofanalysis available for the abovementioned outcomes.

Reference - https://www.beckmancoulter.com/wsrportal/bibliography?docname=361847.pdf