<p>Device for at least partial fractioning or separating fluid from higher density and/or solid particles containing samples, the device comprising a movable or drivable body as e.g. a rotatable plate-like or disc-like body (1) with at least one flow path (3). Within this flow path at one internal wall surface at moving or driving the body the flow velocity of the fluid sample is higher compared with the velocity at e.g. the opposite internal wall surface. At least the one path (3) is comprising at the mentioned one internal wall surface (4) means (5) to at least delay the flow of the fluid sample mixture along the mentioned wall surface. The device is e.g. suitable for the Separation of blood e.g. of plasma from at least red blood cells, preferably from red and white blood cells to achieve blood plasma with high purity for analytical reasons.</p>
