Patent ID: 8377395

Claim:
A separator buoy for use in a fluid collection tube which has at least one inner wall which defines a cavity for containing fluid, the separator comprised of: a body sized and shaped to fit within the cavity and provide a fluid passage between the body and the inner wall, the body comprised of a first resin and a second resin, the first resin having a lower density than the second resin, the first resin and the second resin being present in such amounts and relative proportions so that the body has an overall density between 1.045 and 1.084 and a center of gravity below a geometric center of the body; and a water swellable material attached to the body, the water swellable material being sized and positioned so that when the separator buoy is placed within the cavity and exposed to water containing fluid the water swellable material will swell so as to seal the fluid passage.