Abstract: The present invention is a method and apparatus for precise control of magnetic beads in an optical bio-disc. Embodiments of the present invention use electromagnets for precise control of the forces experienced by the magnetic beads. The use of electromagnets eliminates the need to design precise flow control mechanisms to keep beads in place. This is critical in the stage of washing in an assay, where beads attached to a bottom testing surface are separated from beads that are unattached. One embodiment contains a top electromagnet in a top layer of a bio-disc and a bottom electromagnet in a bottom layer of the bio-disc. Another embodiment is an apparatus of electromagnets that can be used to control the magnetic beads within the optical bio-disc. By adjusting the current flow to the electromagnets, precise control of beads can be accomplished.

Abstract: Apparatus and methods for carrying out biochemical processes directly on a substrate are provided. A substrate assembly includes a cartridge that removably supports a substrate in a fixed position, and a reaction containment member that is removably located on top of the substrate. The reaction containment member includes one or more cavities that form chambers directly above one or more target locations on the surface of the substrate. The chambers can be used to conduct biochemical processes directly over the substrate, as well as to perform thermal cycling of material contained inside the chamber using a heating element disposed directly on the substrate. The substrate assembly is preferably used in combination with a processing machine that dispenses materials into the chambers and that conducts biochemical reactions of materials contained within the chambers, without requiring the substrate assembly to be moved from one location to another location during the processes.