Abstract: A device for isoelectric focusing. The device comprises a focusing container configured to contain an electrolyte solution and having a longitudinal axis and at least one electrolysis unit mounted in a close proximity to the longitudinal axis. Each electrolysis unit injects an ion flow into the focusing container so as to create a pH gradient having a plurality of steps in the electrolyte solution, along the longitudinal axis. Each step has a substantially uniform pH level and the pH gradient is defined by at least one pH ramp between every two sequential steps of the plurality of steps.

Abstract: The present invention provides a mechanism for separating or isolating charged particles under the influence of an electric field without metal electrodes being in direct contact with the sample solution. The metal electrodes normally in contact with the sample are replaced with high conductivity fluid electrodes situated parallel and adjacent to the sample. When the fluid electrodes transmit the electric field across the sample, particles within the sample migrate according to their electrophoretic mobility.

Abstract: With intent to increase the number of sample spots separated through two-dimensional electrophoresis and to enhance the intensity in detection of the spots, a two-dimensional electrophoresis kit includes a first medium 7 for first dimensional electrophoresis, a second medium 8 for second dimensional electrophoresis, and a casing 20 that contains at least the first medium 7 and the second medium 8, wherein the first medium 7 is formed by supplying, to the casing 20, a first solution containing a sample on which the first dimensional electrophoresis is to be performed, and the first medium 7 and the second medium 8 are contained close to each other.

Abstract: A method of separating a mixture of a plurality of molecular analytes having different isoelectric points (pIs). The method comprises placing a solution containing a mixture of a plurality of molecular analytes in a separation volume, generating a pH profile having a plurality of pH zones across an axis of the separation volume, and adjusting a profile of the pH profile to induce a migration of a first molecular analyte along the axis apart from a second molecular analyte. The first and second molecular analytes having different pIs.

Abstract: A device for electrophoresis applies a voltage to a medium in contact with a plurality of electric conductors so that a potential of adjacent conductors is within a certain range. This allows preventing decline in electrophoresis speed. A device for electrophoresis and transfer includes an electrode having a plurality of electrode regions being insulated one another and arranged in a specific direction. This allows providing a practical and easy-to-use device for electrophoresis and transfer. A device for transfer alters an applied voltage or applied voltage duration to a certain position to another position. This allows improving transfer efficiency.

Abstract: Provided are a method and apparatus for measuring an isoelectric point using a field effect transistor. The method includes providing a field effect transistor including a substrate, source and drain electrodes disposed on the substrate and spaced apart from each other, and a channel region between the source and drain electrodes, providing a first electrolyte solution having a first concentration to the channel region of the field effect transistor and measuring a first current value of the channel region between the source and drain electrodes, providing a second electrolyte solution having a second concentration greater than the first concentration and measuring a second current value of the channel region between the source and drain electrodes, and determining the isoelectric point of the field effect transistor or a material disposed on the field effect transistor using a difference between the first and second current values.

Abstract: Disclosed herein is an apparatus for the separation of proteins, comprising a capillary isoelectric focusing unit (2) for primarily separating protein samples on the basis of pI; and a hollow fiber flow field flow fractionation unit (4), connected to one side of the capillary isoelectric focusing unit (2), for secondarily separating the protein samples. The apparatus allows proteins to be separated on the basis of pI and molecular weight without denaturation and can further be applied for the identification of proteins in conjunction with nanoflow liquid chromatography-electrospray ionization-tandem mass spectrometry after enzymatic digestion of the protein fractions.

Abstract: An electrophoresis gel assembly comprising a gel slab, at least two sample wells and at least one focusing buffer well arranged between two adjacent sample wells and wherein focusing barriers are arranged between the focusing buffer well and the sample wells. A high conductivity focusing buffer can be applied to the focusing buffer well to obtain a lateral focusing of the sample bands during electrophoresis.

Abstract: Methods and devices for detecting and collection analytes fractionated based on pI, separating analytes via electrophoresis and pI, and purifying a target molecule using pI focusing and subsequent crystallization are provided.

Abstract: The invention provides methods for detecting an interaction between an analyte and a biomolecule. The method comprises separating at least one biomolecule according to its isoelectric point in the presence of a given analyte and detecting an interaction between the analyte and a biomolecule using fluorescence anisotropy. The method may further comprise collecting the analyte-biomolecule complex and analyzing the biomolecule.

Abstract: A production method of the present invention is a method of producing a reaction instrument for electrophoresis (10), which is constituted by (i) a substrate (1) and (ii) an electrophoresis gel (3) which is immobilized on the substrate (1), including the steps of: (i) discharging a liquid to a surface of the substrate (1) on which surface the gel is to be immobilized, thereby forming a liquid pool (5); and thereafter (ii) discharging a gel solution to the liquid pool (5). This provides a method of producing a reaction instrument for electrophoresis, which method makes it possible to form a gel with high reliability in high yield.

Abstract: The present invention generally relates to devices and methods for the separation of species, including biological species. Some embodiments involve the use of free flow isoelectric focusing (FF-IEF) devices in the separation of a mixture of species. Various device configurations and/or features may enhance the performance of the devices, providing faster and more efficient devices and methods for separating mixtures of species with high resolution. In some embodiments, separation of a mixture of species may be achieved with high resolution and with short sample residence times. Such devices may provide simplified, inexpensive, and optionally disposable devices for the separation of chemical and biological species and may optionally be integrated with orthogonal separation techniques, such as SDS-PAGE or capillary electrophoresis.

Abstract: The present invention contemplates various devices that are configured to separate a sample, which contains more than one unique species, into any desired number of sub-samples by passing the sample across a like number of separation media configured for a first separation protocol. Each of the sub-samples may be further separated by an additional separation protocol, thereby creating a plurality of mini-samples, each of which may be further separated and/or analyzed. The invention also contemplates using a simple method of using conduits to form a fluid path that passes through a plurality of separation media, each of which media is configured to isolate a particular sub-sample. After various sub-samples of the sample are isolated by the various separation media, the conduits may be removed, thereby enabling each of the isolated sub-samples to be further separated and/or analyzed independent of any other sub-sample.

Abstract: An instrument for electrophoresis includes a sample-separating portion in which a slab sample-separating medium that separates a sample is provided. The instrument for electrophoresis includes a sample-transporting portion that transports a sample-containing medium containing the sample to the sample-separating portion. The instrument for electrophoresis includes a positioning portion that is provided to the sample-separating portion and/or the sample-transporting portion and used for connecting the sample-transporting portion to a predetermined position of the sample-separating portion.

Abstract: The procedures involved in isoelectric focusing that entail the use of an electric current can be performed with the gel side of the IPG strip facing either up or down in a tray and electrode assembly in which the electrodes are mounted on an insert from which the inner ends of the electrodes extend into the troughs to reside either below the IPG strips or above them. Slots in one part (either the insert or the tray) mate with walls or partitions in the other part to secure the two parts together, and the heights of the electrodes within the troughs of the tray can be adjusted by the height of the insert in the tray or by a resilient mounting of the electrode to the insert.

Abstract: An ensemble of components and methods are disclosed for utilizing two-dimensional electrophoresis in polyacrylamide or related polymer gels using common, existing and familiar electrophoresis formats and equipment. The disclosed invention makes two-dimensional electrophoresis convenient and easy to use for individuals already using vertical “mini-gel” type systems. The invention discloses the combination of pre-cast disposable gels for both first and second separation dimensions using novel support devices and cassettes that simplify the difficult multiple sample handling and processing steps Inherent in ordinary two-dimensional electrophoresis methods. Devices and methods are disclosed in said invention that provide exceptional gel to gel reproducibility.

Abstract: The present invention is related to a method of separation of compounds by electrophoresis in which the compounds such as genes, proteins, etc. may be analyzed very precisely as samples are introduced directly into the separation tubes of the chip at the collection site, and therefore, it is not necessary to have separate fluid paths or individual sample storing apparatus that have been necessary for the conventional electrophoresis; it is easy to make the chips as the structure of the chip becomes extremely simple, and high-density arrangement of the separation tubes is enabled; and further, the compounds such as genes, proteins, etc. may be analyzed very precisely without interference in the storage tubs by using a non-polar solvent as the solvent of the sample storage tub.

Abstract: The present invention is to provide a sample separation instrument used in a sample separation apparatus which includes: holding means for holding a first medium supporter which supports a first medium; and driving means for moving fixing means or the holding means in a direction parallel or perpendicular to a plane whose sides extend in the first direction and in the second directions. The sample separation instrument includes an insulator for storing a second medium which allows a sample separated in the first medium in the first direction to be further separated in the second direction different from the first direction, wherein: the insulator includes a first opening and a second opening each of which defines the second direction in which the second medium is electrified, and the second opening has a shape which allows the first medium containing the separated sample to be attached to the second medium along the first direction.

Abstract: A concept of high resolution electrophoretic technique, apparatus and its application thereof. The system is a functioning entity in a radial-flat setting. Unlike the conventional rectangular gel-electrophoresis setup, wherein two electrically opposite poles are placed on opposite sites of a rectangular gel, the novel system places one of the electrical poles in the middle of the gel and the outer rims of the radial gel is exposed to the other pole. The point, central pole (positive/negative) and the radial (negative/positive) pole around the outer rim of the gel will create and maintain a gradient electric field, wherein the intensity of the electric field increases towards the central pole with an inverse proportionally to the decrease in the surface area towards the center in a radial-gradient setting.

Abstract: The invention provides methods for detecting an interaction between an analyte and a biomolecule. The method comprises separating at least one biomolecule according to its isoelectric point in the presence of a given analyte and detecting an interaction between the analyte and a biomolecule using fluorescence anisotropy. The method may further comprise collecting the analyte-biomolecule complex and analyzing the biomolecule.

Abstract: The present invention relates to an isoelectric focusing biochip, in particular for fractionating, detecting and/or collecting analytes, such as proteins, metabolites, glycoproteins and/or peptides, a method for fractionating, detecting and/or collecting analytes, with such a biochip and a manufacturing method for such a biochip.

Abstract: The invention relates to devices and methods for the separation of species, including biological species and involves the use of free flow isolectric focusing (FF-IEF) devices capable of establishing a pH gradient in a gradient orientation that is perpendicular to the direction of fluid flow. In one embodiment a channel (224) constructed and arranged to receive a fluid flow, comprises non-parallel sidewalls (230, 240) and at least two electrodes (260,262). In a further embodiment the device comprises a first region comprising a first channel and a second region comprising at least two channels fluidly connected to the first channel.

Abstract: A process for making a support for an electrophoretic medium comprising the steps of: applying an agarose coating to a corona treated polymeric film by transferring a layer of agarose solution onto a surface of the corona treated polymeric film. The pH of the agarose solution can be generally maintained between about 8 and about 11 and the concentration of the agarose solution can be generally maintained between about 0.1 and about 0.4% agarose by weight. The agarose powder used to make the agarose solution can be pre-treated by introducing a fresh reducing atmosphere above the agarose powder and exposing the agarose powder to a reducing atmosphere. The reducing atmosphere treatment may be repeated at least three times.

Abstract: A device providing an arrangement for the separation of a sample mixture for analytical reasons based on multidimensional gel electrophoresis and method thereof are disclosed. The separation involves a first separation in a first dimension of the device on the basis of isoelectric points and a second separation in a second dimension of the device on the basis of molecular size. At least two gel strips for the first dimension separation step and a corresponding gel for the second dimension separation step are provided. The two gel strips are arranged on a single carrier either on the same side or on opposite sides. By having at least two gel strips arranged in such a manner at least two analytical processes can be executed in parallel on the single carrier without the use of valves.

Abstract: A method and apparatus for performing separation of molecules, in particular biomolecules such as nucleic acids and peptides, are disclosed. The method comprises separating molecules by a first characteristic along a linear dimension of a channel, and separating the molecules by a second characteristic along the same linear dimension, with the rust and second separations being carried out within at least partially overlapping sections of the channel. The two separations may then be combined to give a virtual two-dimensional separation which is carried out in a single dimensional real space. The method may also include detecting molecules during the second separation, preferably using an intrinsic characteristic of the molecules for example UV absorbance.

Abstract: Each embodiment includes a central sample reservoir and a plurality of satellite reservoirs. In a first embodiment, a first electrode in electrical contact with the central reservoir is charged and second electrodes in electrical contact with the satellite reservoirs are sequentially charged, thereby pI filtering molecules in the central reservoir into the satellite reservoirs. In a second embodiment, the central reservoir is configured to rotate so that molecules in a sample in the central reservoir are centrifugally pI-filtered into the satellite reservoirs. In a third embodiment, first and second electrodes proximate opposite first and second satellite reservoirs, respectively, are charged. Some molecules in a sample are pI filtered into the first and second satellite reservoirs. Third and fourth electrodes proximate opposite third and fourth satellite reservoirs, respectively, are then charged. Some molecules in a sample are pI filtered into the third and fourth satellite reservoirs.

Abstract: The present invention provides a novel and advantageous method for separating analytes by free flow electrophoresis. The methods are particularly suitable for depleting major constituents such as albumin from samples of biological origin, optionally combined with a further separation of the remaining portion of the sample. The sample portions recovered from the method can be used advantageously in downstream applications such as 1D or 2D-PAGE, HPLC or mass spectrometric analysis. Also provided are buffer systems, kits comprising such buffer systems, and devices for carrying out the free flow electrophoretic separation methods of the present invention.

Abstract: The procedures involved in isoelectric focusing that entail the use of an electric current can be performed with the gel side of the IPG strip facing either up or down in a tray and electrode assembly in which the electrodes are mounted on an insert from which the inner ends of the electrodes extend into the troughs to reside either below the IPG strips or above them. Slots in one part (either the insert or the tray) mate with walls or partitions in the other part to secure the two parts together, and the heights of the electrodes within the troughs of the tray can be adjusted by the height of the insert in the tray or by a resilient mounting of the electrode to the insert.

Abstract: The present invention relates to methods and devices for forming a plurality of wells on a gel containing an analyte. The invention further provides a system for eluting a liquid analyte reagent mixture from a gel. The invention is useful in the separation of biological molecules such as nucleic acids, carbohydrates, proteins and peptides. In particular, the invention has utility for separating and eluting peptides from isoelectric focusing gels.

Abstract: The present invention relates to an electrode bridge or sample application bridge for use in electrophoresis, preferably isoelectric focusing, IEF. More closely, the invention relates to an electrodic bridge or sample loading bridge for preventing denaturant depletion from the IPG (immobilised pH gradient) gel and, optionally, for loading samples onto the IPG gel. The pH of the bridge is adjustable for adoption to positioning at the acid as well as basic end of the IPG strips.

Abstract: A device and a method for multidimensional separation and analysis of molecules is disclosed. The device comprises a chamber for subjecting a first substance to a first analysis step and a space for receiving a second substance. The device is configured to apply pressure to the second substance to move the second substance towards a product of the first analysis step for providing a sample for a second analysis step.

Abstract: Methods and apparatus are presented that facilitate electrophoresis of prior-cast, hydratable separation media, usefully immobilized pH gradient (IPG) strips. The method exploits the swelling of prior-cast, hydratable separation media upon rehydration to help lodge the media in an enclosing member that permits spaced electrical communication with the enclosed separation media. The electrical communication permits a voltage gradient to be established in the enclosed separation medium sufficient to effect separation of analytes therein. Cassettes, buffer cores, electrophoresis systems and kits are presented for effecting the methods of the invention.

Abstract: An ensemble of components and methods are disclosed for utilizing two-dimensional electrophoresis in polyacrylamide or related polymer gels using common, existing and familiar electrophoresis formats and equipment. The disclosed invention makes two-dimensional electrophoresis convenient and easy to use for individuals already using vertical “mini-gel” type systems. The invention discloses the combination of pre-cast disposable gels for both first and second separation dimensions using novel support devices and cassettes that simplify the difficult multiple sample handling and processing steps inherent in ordinary two-dimensional electrophoresis methods. Devices and methods are disclosed in said invention that provide exceptional gel to gel reproducibility.

Abstract: An ensemble of components and methods are disclosed for utilizing two-dimensional electrophoresis in polyacrylamide or related polymer gels using common, existing and familiar electrophoresis formats and equipment. The disclosed invention makes two-dimensional electrophoresis convenient and easy to use for individuals already using vertical “mini-gel” type systems. The invention discloses the combination of pre-cast disposable gels for both first and second separation dimensions using novel support devices and cassettes that simplify the difficult multiple sample handling and processing steps inherent in ordinary two-dimensional electrophoresis methods. Devices and methods are disclosed in said invention that provide exceptional gel to gel reproducibility.

Abstract: The present invention relates to a method for pre-fractionation of complex protein and/or peptide samples. The method comprises the following steps: a) loading the sample onto pre-packed media able to separate proteins/peptides according to their pl-value; b) eluting the media by centrifugal force under denaturing conditions with at least three buffers having different pH in a stepwise manner to obtain at least three fractions separated according to pl-value; and c) subjecting each fraction to further separation in a pH-range corresponding to the pl-values of said fractions. The invention also relates to a kit comprising at least one spin column or multiwell plate filled with chromatography medium able to separate proteins/peptides according to pl-value, at least three buffers, and one or more IPG strips having a narrow pH-range adapted to each of said buffers.

Abstract: The invention relates to a device for electrophoretically separating molecules. The inventive device comprises: at least one plate having a top side and an underside; a first separating channel provided for receiving at least one first separating medium; at least one second channel, which is orthogonal to said first separating channel and which is provided for receiving a second separating medium; optionally comprises implements provided for filling the device with reagents, solvents, buffers, separating media and/or for loading the device with a sample to be separated, and; terminals for applying electric separating voltage to the separating channels. In the device, the first separating channel is located on the plate top side and comprises at least one first opening that leads to the plate underside, whereby the second separating channel is located on the plate underside and comprises at least one second opening.

Abstract: The invention relates to a separation medium for chromatography which is structured in that way that the flow rate is in one preselected direction larger than perpendicular to that direction.

Abstract: The invention relates to a device and a method for automatically analysing the constituents of at least one analyte, especially by means of gel electrophoresis and/or isoelectric focussing, comprising at least one separating matrix, especially a gel. Each separating matrix is applied on at least one side in a supporting direction S of a supporting element, can be loaded with an analyte, and can be electrically contacted on opposite ends in a separating direction T in order to split the analyte into its constituents.

Abstract: The present invention relates to electrophoresis and in particular electrophoretic gel composites used for separation of biomolecules, such as proteins and peptides. More particularly, the invention relates to gel composites with improved oxygen barrier properties. The invention provides an electrophoretic gel composite, comprising a) a polymer support; b) an electrophoretic hydrogel; and c) an oxygen barrier film between the polymer support and the hydrogel. Preferably the hydrogel is produced in the presence of an oxygen scavenger and/or under inert atmosphere. The improved oxygen barrier properties make the gel composites excellent for electrophoresis without artifacts in the gel.

Abstract: The invention relates to a medium for analytic and preparative electrophoresis which includes a content of acids and bases of different pKa values. The medium contains at least two acids, where the difference in pKa values (?pKa) of adjacent acids are no greater than 1.0, preferably in the range from 0.8 to 0.5. The medium also contains at least two bases, whose pKa values range from approximately 1.5 to 11, and the difference of the pKa values (?pKa) of adjacent bases is no greater than 1.0, preferably in the range from 0.8 to 0.5.

Abstract: A device for two-dimensional electrophoresis includes a cassette comprising two opposing plates. The two opposing plates form a first elongated portion for receiving a first elongated electrophoretic separation medium and a second portion extending away from the first portion. A second electrophoretic separation medium is on the second portion and between the two opposing plates. A dialysis membrane extends across the second electrophoretic separation medium.

Abstract: A device includes a substrate having first and second major surfaces and a hub that defines an axis of rotation for the substrate, and an unvented channel having a plurality of connected compartments. Methods for using devices of the invention are also disclosed.

Abstract: A multielevational cover for assembling a fluid retaining chamber on a face of an electrophoresis cassette is presented. The cover comprises a cassette-containing member, at least one chamber-defining member, and sealing means, typically sealing means that are capable of reversible attachment. Also presented are methods for contacting cassette-immobilized gels to desired fluids by assembling a fluid retaining chamber upon the cassette using the covers of the present invention.

Abstract: The present invention relates to matrixes, arrays, systems and methods for analyzing biomolecules by their isoelectric point, optionally, in combination with a second dimension analysis. The assortment of matrixes, arrays and systems provided herein are useful for causing a biomolecule under the influence of an electrical field to accumulate into an IEF buffer that comprises a pH value that is the same as the isoelectric point of the biomolecule. The methods of this invention are useful for, e.g., research and diagnostic purposes.

Abstract: A gel electrophoresis cassette (33) is disclosed which includes two plates (34, 35) and at least one seal (36) which separates these plates. The seal (36) is annular; it may be positioned essentially in the region of the outer edge of the plates (34, 35). For performing an electrophoresis in a second dimension following an isoelectric focusing in an first dimension, one of the plates (34, 35) includes a recess (37) for inserting a strip holder (1) having a base plate (4), which has a carrier surface (2) on which an IEF strip (3) is accommodated. The base plate (4) includes at least one stop (5) offset to a lower level in relation to the carrier surface (2) and a sealing surface (6). The strip holder (1) is insertable into this recess (37) in such a way that the stop (5) of the base plate (4) is applied to the outer surface of the plate (34, 35) and the sealing surface (6) presses tightly against the inner surface (38) of the recess (37).

Abstract: A strip holder (1) is disclosed for accommodating a gel strip (3) for separating molecules using gel electrophoresis. The strip holder (1) disclosed is distinguished by including a baseplate (4), at least one stop (5), which is offset to a lower level in relation to the carrier surface (2), and at least one sealing surface (6), this stop (5) being implemented to be applied to counter surfaces (7) of an electrophoresis chamber, through which offset to a lower level of the stop (5) the installation depth of the strip holder (1) carrying a gel strip (3) into this electrophoresis chamber is determined and the sealing surface (6) ensuring a sealing installation of the strip holder (1) carrying a gel strip (3) into this electrophoresis chamber. Such a chamber (15) for isoelectric focusing of molecules in gel strips (3) is distinguished by including such a strip holder (1), a frame (16), and a cover (20).

Abstract: Carboxylic acid-substituted polyalkylene polyamines in which amine nitrogen atoms on the polyamine backbone structure are replaced by guanidine groups provide a pH range extending into high pH values. These substances are useful as carrier ampholytes in isoelectric focusing.

Abstract: A system for separating biological molecules includes a chip (10) on which there is an electrophoresis separation microchannel (16). At the start of the channel there is an isoelectric focusing section (14) containing a gel having a pH gradient. Molecules to be separated are placed in the focusing section (14) and move to an equilibrium position under the influence of an electric field. The electrophoretic state of the molecules is then changed, and a high voltage potential applied across the entire length of the focusing and separation sections. The molecules migrate under the influence of the electric field from the focusing section into the separation section where their position and velocity are tracked. From a knowledge of position and velocity, a user can determine both charge/mass ratio and isoelectric equilibrium point for each molecule. The gels can be replicated in the chip to allow parallel analysis, and hence comparisons, to take place.

Abstract: An apparatus for rehydrating and for performing electrophoresis on a gel strip includes a tray defining a plurality of parallel troughs configured to receive gel strips. Each trough defines a centrally located rehydration area and an electrode area disposed either side of the electrode area. End walls delimit the rehydration area of the trough from the electrode area. Electrode means including contact points adapted to contact either the gel strip in the electrode areas near the first and second end of the gel or a conducting or current carrying electrode bridge material which is in contact with the gel strip in the electrode areas. The electrode means are adapted to be connected to a means for supplying an electric current for imposing an electric potential in the strip between the electrodes.

Abstract: Improved apparatus is disclosed for carrying out axially illuminated laser induced fluorescence whole-column imaging detection in the capillary isoelectric focusing of proteins. The separation capillary was made of low refractive index Teflon conditioned with methylcellulose to reduce electroosmotic flow and a small amount of high refractive index organic solvent (glycerol) was added to the sample mixture. It was found that an axially directed laser excitation beam was propagated essentially with total internal reflection, so that minimum interference arose from stray light or from scattering light originating from the wall of the capillary. With the naturally fluorescent protein R-phycoerythrin, a concentration detection limit LOD 10?11 M or mass LOD 10?17 Mo was obtained.