Abstract: A preparative electrophoresis apparatus suitable for recovery of molecules from gels comprises two spaced apart electrode compartments connected by a conduit that descends from the bottom of the electrode compartments in a V-shaped or U-shaped form. The conduit serves as a reservoir for collecting electroeluted molecules. Two electrophoresis buffers are used, a first one of a low concentration and density, and a second one of a high concentration and density. The electrode compartments are filled with the first electrophoresis buffer solution while the conduit is filled with the second electrophoresis buffer solution. Under the influence of an electric field, the molecules exit the gel and concentrate in the high concentration buffer. After a certain time, usually a time that is sufficient for driving substantially all desired molecules out of the gel, the electric field is switched off. The high concentration buffer containing the electroeluted molecules is withdrawn from the conduit.

Abstract: The device of present invention is used for cutting and recovery of a selected gel piece from a larger gel mass. The gel piece suitably contains molecules that will be used in further work. The preferred device is made up of at least two parts: a hollow member with a distal end terminating in a cutting edge, a proximal end, and a lumen in between the proximal and distal ends; and a piston member. The lumen part of the hollow member close to the proximal end has a larger cross section than a lumen part close to the distal end. The piston body has at least a first body that fits snugly in the lumen part having the larger cross section and a second body is longer than length of the lumen part with a smaller cross section and fits within the smaller cross section portion of the hollow tube, creates reduced pressure when moved towards proximal end of the hollow tube is disposed within the lumen.

Abstract: A gel for electrophoresis in a horizontal mode which contains at least one sample well with an enlarged loading area that is formed in an elevated gel segment. At least a front wall of the sample well consists of a substantially vertical part and a non-vertical part, where the non-vertical part is declined at an angle sufficiently steep that the sample loaded on the non-vertical part slides down into the sample well. Any sample molecules that during electrophoresis enter the gel through the non vertical part of the front wall migrate only through the elevated gel segment. They also exit this segment, so that substantially no double bands, which could complicate the interpretation of experimental results, are detected.

Abstract: Electrophoresis gels of enhanced selectivity are produced by adding a preformed polymer to a polymerization solution containing at least one monomer and at least one cross-linker. The polymer must be of such a chemical composition and molecular weight that its presence during free-radical polymerization results in a new topology of gel polymers, so that under the influence of an electric field, such as during electrophoresis, the passage of long DNA molecules through the gel is retarded proportionally more than the passage of the short ones. The polymer needs to be added at specific ratio to the monomer and the cross-linker, and the enhanced selectivity is achievable only within a certain range of ratios of polymer(s), monomer(s) and cross linker(s). That range is dependent on all three essential gel components, the polymer, the monomer and the cross-linker.

Abstract: A gel for electrophoresis in a horizontal mode which contains at least one sample well with an enlarged loading area that is formed in an elevated gel segment. At least a front wall of the sample well consists of a substantially vertical part and a non-vertical part, where the non-vertical part is declined at an angle sufficiently steep that the sample loaded on the non-vertical part slides down into the sample well. Any sample molecules that during electrophoresis enter the gel through the non-vertical part of the front wall migrate only through the elevated gel segment. They also exit this segment, so that substantially no double bands, which could complicate the interpretation of experimental results, are detected.

Abstract: A bed of water insoluble, transparent, cross-linked gel, suitable for use in electrophoresis, is formed by dissolving a polysaccharide, including at least one linear polysaccharide such as agarose or hydroxyethyl cellulose, in a suitable solvent, such as water; adding a cross-linking agent, which is not charged nor becomes charged upon contact with water in a pH range of 2 to 11, to the solution; and incubating this mixture in a quiescent state to substantially simultaneously react the polysaccharide and the cross-linking agent and to gel the reaction product into a bed. The polysaccharide is at least one linear polysaccharides, but that linear polysaccharide may also be admixed with other linear polysaccharides and/or at least one non-linear polysaccharide. Synthetic organic polymers may also be admixed in the cross-linking reaction mixture.

Abstract: A bed of transparent, water insoluble, charge-free crosslinked gel which is suitable for use in electrophoresis is prepared. The gel is formed by dissolving a linear polysaccharide, such as agarose, in a suitable solvent, such as water. This dissolution may be accomplished with agitation. A suitable cross linking agent, which is not itself charged, nor does it become charged upon contact with water, at a pH of 2 to 12, is then added to the solution, possibly with agitation in order to get thorough mixing of the linear polysaccharide and the cross linking agent. This mixture is then allowed to incubate and react in a quiescent state to substantially simultaneously gel and crosslink to form the desired cross linked gel bed. Preferred cross-linking agents are bis-epoxides, halo-epoxides, bis-haloalkanes, bis-halo-alcohols, alkanediol-bis-alkyl sulfonates, alkanediol-bis-aryl sulfonates or divinylsulfone. The liner polysaccharide maybe mixed with a synthetic polymer such as polyvinyl alcohol.