Abstract: A centrifuge vessel is configured to have at least two chambers therein separated by a divider, and with a spillway around a lip at an end of the divider to join the chambers. After centrifugation differing density phases of an original sample remain on opposite sides of the divider. Separate extraction ports are provided for removal of differing density phases of the original sample from opposite sides of the divider. A method of use of the centrifuge vessel includes centrifugation and extraction at differing orientations of the vessel for convenient and reliable extraction of differing density fractions from the original sample.