History of AUC Instrumentation

High speed centrifugation was first developed one hundred years ago, in the 1920's, while the knowledge of centrifugation has been around for centuries.

It was in Uppsala, Sweden, where Theodor "The" Svedberg build the first ultracentrifuge with his co-workers in 1924. This instrument utilized a hydrogen atmosphere and sector shaped cells. Svedberg was initially interested in gold particle size distributions, but was redirected to performing sedimentation equilibrium experiments to study the tertiary and quaternary structures of proteins. Click here to read Theodor's paper on protein molecules.

The first sedimentation velocity experiment verified a hemo-globin mass, which was identical to the 68,000 g/mol that was measured by the equilibrium experiment, and confirmed the presence of a single diffusion component.

In the 1940's, Edward Pickel developed an ultracentrifuge that would perform under vacuum, greatly reducing heat from any frictional interactions. Edward Pickel also started SPINCO (Specialized Instruments Company), which was later acquired by Beckman (now Beckman-Coulter). The Model E also allowed for the development of the Rayleigh interferometric optical system,1 and the photoelectric scanning absorbance optical system.2 The short column technique for sedimentation equilibrium34 and density gradient equilibrium experiments5 were developed in parallel.

AUC was left behind as newer and faster analytical methods were developed, but when Beckman introduced the XL-A instrument in 1992, its use increased. This newer AUC produced digital absorbance data, were smaller, and overall more easily maintained and serviced. Today, AUC is a powerful technique in biophysics for several reasons:

  1. AUC has unmatched resolution due to hydrodynamic separations of all molecules based on their size, density, and anisotropy.

  2. AUC does not require any standards, as it is a first principle technique, and a partial differential equation (the Lamm Equation) can exactly describe the flow of solution within an AUC cell.

  3. AUC has a large dynamic range, with variable rotor speed, allowing for variable buffer densities and viscosities, with high sensitivity from pico-molar to high micro-molar concentrations.

  4. AUC has multiple optical systems which can provide orthogonal measurements.

  1. Richards, E. G., & Schachman, H. K. (1959). Ultracentrifuge Studies with Rayleigh Interference Optics.I. General Application. The Journal of Physical Chemistry, 63(10), 1578-1591. https://doi.org/10.1021/j150580a008
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  2. Hanlon, S., Lamers, K., Lauterbach, G., Johnson, R., & Schachman, H. K. (1962). Ultracentrifuge studies with absorption optics. Archives of Biochemistry and Biophysics, 99(1), 157-174. https://doi.org/10.1016/0003-9861(62)90258-8
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  3. Van Holde, K. E., & Baldwin, R. L. (1958). Rapid attainment of sedimentation equilibrium. The Journal of Physical Chemistry, 62(6), 734-743. ↩

  4. Yphantis, D. A. (1964). Equilibrium ultracentrifugation of dilute solutions. Biochemistry, 3(3), 297-317. ↩

  5. Meselson, M., Stahl, F. W., & Vinograd, J. (1957). Equilibrium sedimentation of macromolecules in density gradients. Proceedings of the National Academy of Sciences, 43(7), 581-588. ↩