Patent ID: 8119013

Claim:
A method of isolating and withdrawing a selected component from a multiple component material using a buoy, comprising: filling a separation container with the multiple component material, the separation container having a buoy with a tuned density, wherein the separation container defines a container longitudinal axis; centrifuging the separation container to cause the multiple component material to separate into at least two fractions of varying densities by, allowing the buoy in the separation container to reach an equilibrium within the fractions, positioning at least a portion of one of the two fractions within a collection space near the buoy, and conveying the selected component of at least one of the two fractions along a guide surface of the buoy to an accumulation position near a perimeter of the buoy, wherein the buoy has a buoy maximum transverse dimension that is defined by a line that is transverse to the container longitudinal axis and the guide surface is inclined substantially through the container longitudinal axis and relative to a buoy sidewall for at least two-thirds of the buoy maximum transverse dimension of the buoy; and withdrawing the selected component.