Analytical band centrifugation

Analytical band centrifugation (ABC) (also known as analytical band ultracentrifugation, or band sedimentation-velocity), is a specialized ultracentrifugation procedure, where unlike the typical use of (boundary) sedimentation velocity analytical ultracentrifugation (SV-AUC) wherein a homogenous bulk solution is centrifuged, in ABC a thin (~15 μL, ~500 μm)[1] sample is layered on top of a bulk solvent and then centrifuged.

The method is distinguished from zone-sedimentation in that a stabilizing density gradient is self-generated during centrifugation, through the use of a higher density (than the sample) bulk "binary solvent", containing both a solvent (i.e. H2O), and a second component (small molecules, i.e. CsCl) that will sediment to form a stabilizing density gradient for the sample.

[2] ABC also requires specially designed analytical ultracentrifuge cells, as the sample is not manually applied by pipette but instead automatically delivered via capillary under low g-forces at the beginning of a run from a reservoir within the cell.

It was first demonstrated in 1963,[2] and was not commonly used for many decades,[3][4] but recently has become more widely used due to its applicability to quality control measurements on therapeutic viruses such as adeno-associated viruses (AAVs).

[1] The profiles resulting from ABC analyses are similar in their interpretation to the profiles from electrophoretic separations ("electropherograms"), and thus have been dubbed "centrifugrams".