Abstract: The method and apparatus for preparative electrophoresis is especially useful for proteins. An electrophoretic potential with an initial polarity is applied across an electrophoretic medium (13) to induce at least two species of macromolecules (1,2) in a mixture (3) with a first electrolyte solution to move into the medium (13) and towards a second electrolyte solution on an opposite side of the medium (13). The at least two species of macromolecules (1,2) have similar transport properties, although at least one (1) of the species moves through the medium (13) at a faster rate than the other species (2). The initial polarity is maintained until just before any of the other species of macromolecules have emerged into the second electrolyte solution whereupon the polarity of the electrophoretic potential is reversed while preventing the proportion of the at least one species of macromolecules (1) which has already emerged into the second electrolyte solution from being drawn back into the medium (13).

Abstract: A cassette for holding an electrophoretic gel. The cassette has two substantially planar wall members formed of a synthetic plastics material, each wall member having two sides and two ends. The wall members are formed integrally along each side with an array of interdigitating ribs and grooves which releasably hold the wall members in substantially parallel array spaced apart sufficiently to define between them an electrophoretic gel receiving space. The ribs and grooves also serve to form a substantially fluid tight seal down each side of the gel receiving space. A plurality of ribs extend between the upper edges of the two wall members to define a series of wells above the gel into which samples to be electrophoretically separated may be placed.

Abstract: The method for electrophoretic transport of at least one solute from a first solvent stream to a second solvent stream utilizes an apparatus having a housing, a pair of electrodes positioned with the housing, each electrode being positioned adjacent one of a pair of opposite ends of the housing and each being surrounded by a device to provide a flow of a buffer around the electrode, a first inlet device through which the first solvent stream is introduced into the housing and an associated outlet device, a second inlet device through which the second solvent stream is fed into the housing and an associated outlet device, a plurality of electrophoretic membranes extending in substantially parallel, space apart, array transversely of the housing and between the electrodes, the membranes being structured to define a first solvent path for the first solvent stream and a separate second solvent path for the second solvent stream.

Abstract: A method and device for the preparative scale recovery of a protein or other charged macromolecule by electrophoretic separation of a mixture of such macromolecules. The device is adapted to be installed between the electrodes of an electrophoretic cell and includes a gel receiving receptacle adapted to hold the end of a gel slab or gel fragments containing an electrophoretically separated macromolecule. An aperture in the base of the receptacle is covered by a first membrane which is substantially permeable to the macromolecules desired to be recovered and a second membrane substantially impermeable to the macromolecules to be recovered but permeable to electrolyte molecules in a buffer solution used in electrophoresis. The two membranes lie in spaced apart array with one another to define therebetween a recovery space. Means are provided to allow the periodic or continuous withdrawal of buffer solution and macromolecules from the recovery space.

Abstract: An apparatus and method of determining the end point of a chemical reaction producing an optical change in a plurality of samples is disclosed. The invention is particularly suitable for the simultaneous determination of the coagulation time for multiple samples of blood and like materials.