Abstract: The cover for a fixed angle centrifuge rotor has an array of container support surfaces depending from the lower surface thereof. Each support surface is substantially cylindrical in configuration and has an axis associated therewith. Each container support surface is associated with a respective one of the cavities formed in the rotor body. In the most general case, when the rotor cover is attached to the rotor body, the axis of each container support surface lies in the same common radial plane as do the axis of the cavity with which the support surface is associated and the axis of rotation. In the common radial plane, the axis of a support surface is inclined at a predetermined angle with respect to the axis of rotation. The axis of the support may further be arranged to lie in parallel relationship to the axis of the cavity with which it is associated, or may define a predetermined angle with respect thereto.