Abstract: According to one aspect of the invention, a method of creating a dilution series is provided. The method may include providing a first vessel including a sample, and aspirating at least a portion of the sample from the first vessel into a first conduit primed with solvent such that the sample disperses in the solvent. At least a portion of the dispersed sample is dispensed into a second vessel while, substantially simultaneously, a solvent is dispensed into the second vessel from a second conduit. Alternatively, the second vessel may already contain the solvent and the first conduit may dispense the dispersed sample into the second vessel containing the solvent. According to one aspect of the invention, a system for creating a dilution series is provided. The system may include a first conduit configured to aspirate and dispense a sample to be diluted and a second conduit configured to dispense a solvent.

Abstract: A universal fluid exchange device includes upper and lower reaction vessel supports which include pressure sealed injection and evacuation ports for each supported reaction vessel. Reaction vessels matingly engage through the injection and evacuation ports with fittings which are connected through flexible tubing to respective supplying and receiving vessels. The reaction vessels or fittings are moved into position, as required, so that reactants may be directly supplied from supplying vessels in the order and amount desired without operation of valves that can become contaminated, and so that the reaction vessels may dispel their contents into the appropriate receiving vessels. The system may be highly advantageous in applications such as combinatorial chemistry where myriad combinations of chemicals, solvents and reagents are employed.

Abstract: A positive displacement positioner employs rigid stops and actuators to position a work piece, such as a microtiter plate, in any one of at least three positions. Positioner platforms, each of which is capable of moving a work piece between at least two distinct positions, are nested in order to multiply the number of positions available. For example, a two-position rigid stop positioner platform nested in a four-position rigid stop positioner platform, or a four-position rigid stop positioner platform nested in a two-position rigid stop positioner platform would permit the movement of a work piece to any one of eight distinct positions. A four-position platform nested inside a four-position platform yields sixteen positions, and so on. Each positioner platform preferably has a symmetrical polygonal outline and nested platforms provide displacement along each of the polygon's axes of symmetry. Consequently, a positioner will preferably provide displacement to any one of a number of positions.