Patent ID: 8062533

Claim:
A spin column assembly, comprising: a) a spin column device, the spin column device comprising: 1) a column, the column comprising an inner diameter and an upper opening, 2) a lower end, the lower end comprising an effluent port, wherein the effluent port comprises an opening small enough to retain or impede the exit of solid or particulate matter from the spin column device, but large enough to allow passage of effluent liquids; b) a separation media suspension contained within the spin column device, the separation media suspension comprising an upper surface; c) a rigid porous filter placed within the spin column device above the separation media suspension and in close contact with the upper surface of the column separation media suspension, the porous filter comprising a filter diameter no greater than or equal to the inner diameter of the spin column and a filter height greater than half the inner column diameter; d) a volume control device for regulating the volume of fluid delivered to the upper surface and center of the spin column assembly, wherein the volume control device is placed within the upper opening of the spin column device and above the rigid porous filter, the volume control device comprising: i) an outer column; ii) a base attached below the outer column, the base comprising a hole, wherein the hole in the base impedes or prevents the flow of fluid due to surface tension effects under normal gravity, but permits the flow of fluid through the hole under higher gravitational or other forces; e) a hollow inner cylinder attached to the base and situated within the outer cylindrical column, the inner cylinder comprising a height and inner diameter; f) a first cavity within the hollow inner cylinder and above the base comprising a fixed volume, wherein the height and inner diameter of the inner cylinder determines the fixed volume; and g) a second cavity outside the inner cylinder, but within the outer column and above the base, wherein any excess of fluid delivered to the first cavity will overflow and be retained in the second cavity without being delivered to the upper surface of the spin column assembly and only the fluid in the first cavity will pass through the lower opening onto the receiving spin column assembly.