| abstract |
It is known to use high centrifugal forces to separate the two phases of a two-phase liquid. However, high centrifugal forces may produce an inseparable layer between the two phases which is includes useful material, for example cells containing DNA. Disclosed herein is an improved method for phase separation of whole blood. The method includes the use of a device (30) which allows much lower centrifugal forces to be used. As a result, leukocytes are separated from blood cells having specific gravities of 1.08x10<3>kgm<-><3> or higher. The method preferably uses a separation chamber (32) arranged so that its long dimension ( l ) is parallel, not perpendicular, to spin axis (76). A valve (50) opens in response to a hydraulic head of force and not to the effects of cnetrifugal force, to allow automatic removal of the lighter phase(s). Advantageously, this method shortens conventional procedures for the extraction of DNA from whole blood. |