Abstract: A device for positioning a component thereof along x- and y-axes of the device is provided. The device includes first and second motors, a carriage containing the component to be positioned, a lead screw to position the carriage along a first axis of the device, and a keyed shaft to position component to be positioned along a second axis of the device. The first motor drives the lead screw and the second motor drives the flatted shaft. In some embodiments described herein, the flatted shaft turns a first pulley, which is connected to a second pulley by a belt. The component to be positioned is attached to the belt and moves along a second axis of the device as the belt moves.

Abstract: The present invention is directed to a device for positioning a component thereof along x- and y-axes of the device. The device includes first and second motors, a carriage containing the component to be positioned, a lead screw to position the carriage along a first axis of the device, and a keyed shaft to position component to be positioned along a second axis of the device. The first motor drives the lead screw and the second motor drives the flatted shaft. In some embodiments described herein, the flatted shaft turns a first pulley, which is connected to a second pulley by a belt. The component to be positioned is attached to the belt and moves along a second axis of the device as the belt moves.

Abstract: A system for separating a sample and collecting the separated sample. The system includes an ultracentrifuge having a cylindrical rotor. The system includes a gradient delivery assembly for delivering a gradient solution to the ultracentrifuge rotor, and a sample delivery assembly for delivering the solution containing the sample to the ultracentrifuge rotor. he system includes a fraction collection assembly for collecting discrete volumes of the separated sample. The system includes a processor for controlling operation of the ultracentrifuge, as well as the gradient delivery assembly, the sample delivery assembly, and/or the fraction collection assembly.