Patent ID: 8394342

Claim:
A separation assembly for enabling separation of a fluid sample into first and second phases, comprising: a tube, having an open end, a second end, and a sidewall extending therebetween; a closure adapted for sealing engagement with the open end of the tube, the closure defining a recess; and a mechanical separator releasably engaged within the recess, the mechanical separator comprising: a float comprising a passageway extending between first and second ends thereof with a pierceable head enclosing the first end of the float; a ballast longitudinally movable with respect to the float; and a bellows extending between a portion of the float and a portion of the ballast, the bellows adapted for deformation upon longitudinal movement of the float and the ballast, the bellows isolated from the pierceable head, wherein both the pierceable head and the bellows comprise a thermoplastic elastomer.