Abstract: A fractionation apparatus has a displaceable piston operably mounted for displacing liquids from a centrifuge tube as the piston is inserted therein. The fractionation apparatus has a collection tip which has a seal for sealingly engaging an inner wall of the tube and has an axially extending passageway for passing liquids from within the tube to a collector as the piston is inserted into the tube. The passageway is generally a trumpet shape having a wide end and a narrow end. The wide end is presented to the liquids and the narrow end connects to the collector. The trumpet shape enhances laminar flow through the collection tip and reduced unwanted mixing between layers during fractionation.

Abstract: An apparatus for conducting a blotting process comprises a support member, a first electric motor for rotating the support member about a vertical plane, a tube holder having a substantially flat surface for magnetically mounting at least one tube, a second electric motor for rotating the tube holder and a control for controlling the second electric motor. The tube holder is mounted for rotation on the support member. The tube is secured within the tube holder, the support member is rotated at a predetermined angle and the tube holder is rotated at a predetermined speed blotting reagent onto a filter.

Abstract: An apparatus for generating a continuous solution gradient wherein solutions of differing concentrations are layered in a tube and the tube disposed at an angle with respect to the vertical and is rotated for a predetermined period of time thereby to generate a continuous solution gradient, i.e. continuous variation in concentration between the concentration of the initial solutions.

Abstract: A process and apparatus for generating a continuous solution gradient wherein solutions of differing concentrations are layered in a tube and the tube disposed at an angle with respect to the vertical and is rotated for a predetermined period of time thereby to generate a continuous solution gradient, i.e. continuous variation in concentration between the concentration of the initial solutions.

Abstract: A method and apparatus for the fractionation of centrifuged density gradients have been developed. The apparatus consists of a gradient holder composed of a transparent and an opaque section which contains an opening allowing a centrifuged tube containing a density gradient having individual bands to be inserted into the holder. A displaceable piston which is suspended above the holder and is connected to an actuator may be raised or lowered into the density gradient. A standard illuminating device is placed under the gradient holder so that the exact position of each individual band can be determined. Once the precise location is determined, the displaceable piston is lowered into the gradient and by operating the actuator, the desired band of gradient can be extracted. Additionally, this method may be utilized in a continuous fractionation of the entire gradient.