Abstract: An adjustable supporting arrangement used within the sample receiving cavity of a centrifuge rotor to hold and align a plurality of test tubes. The arragement is comprised of a series of similarly configured interface layers which can be variably arranged to accommodate different sized test tubes. A bracket member is utilized to retain the alignment of the various interface layers and hold them as a single unit for convenient movement into and out of the rotor cavity. Incorporated within the supporting arrangement is a separate cushion pad to receive the bottom ends of the test tubes. A uniquely designed divider plate can be placed within the supporting arrangement to partition the rotor cavity into two areas for receipt of two sets of test tubes in stacked relation.

Abstract: In a centrifuge rotor of the type including a yoke and an enclosure for the yoke, the enclosure being operatively connected to the yoke for rotation therewith, the enclosure comprising a wind shield physically connected to the bottom of the yoke and extending beneath the yoke and around the sides thereof and a lid being positionable over the yoke to engage the wind shield for completely enclosing the yoke, there is disclosed a method and means for retaining the lid in contact with the wind shield wherein the wind shield terminates in an upwardly facing circular lip and the cover terminates in a downwardly facing circular lip so that the lip of the lid engages the lip of the wind shield, there being no physical connection between the lid and the wind shield, the lid being retained in contact with the shield during rotation of the centrifuge rotor by the force created by the naturally-occurring low pressure within the enclosure, beneath the lid.