Abstract: The present technology relates to improved device and methods of use of insulator-based dielectrophoresis. This device provides a multi-length scale element that provides enhanced resolution and separation. The device provides improved particle streamlines, trapping efficiency, and induces laterally similar environments. Also provided are methods of using the device.

Abstract: In described examples, bootstrap diode circuits include a first diode having a first diode input coupled to a voltage supply and a first diode output. Described bootstrap diode circuits additionally include a second diode having a second diode input coupled to the first diode output and a second diode output and a plurality of zener diodes coupled in series. The series-coupled zener diodes are further coupled in parallel with the second diode.

Abstract: The invention is a multiplex, pulsed-field capillary electrophoresis instrument with the ability to analyze DNA fragments with sizes greater than 150,000 base pairs. The parallel capillary electrophoresis system allows for the simultaneous analysis of at least 12 samples while applying a pulse or varying electric field for separation. Sequences of pulse-field electric fields are iterated to achieve accurate separation of DNA smears.

Abstract: Methods, devices, and apparatus, including computer programs encoded on a computer storage medium for reconstructing an image are provided. An example method includes: acquiring Computed Tomography (CT) projection data of a subject, determining an image cutoff frequency Fimg according to a CT image matrix size for reconstructing a CT image and an imaging field of view size, obtaining a convolution kernel and a cutoff frequency Fker of the convolution kernel, using the convolution kernel as a reconstruction convolution kernel when Fker<Fimg; adjusting Fker to a product of a preset value k and Fimg and truncating the convolution kernel to obtain a portion of the convolution kernel having a cutoff frequency no more than the adjusted Fker as the reconstruction convolution kernel when Fker?Fimg, and reconstruct the CT image with the CT projection data and the reconstruction convolution kernel by using a convolution back-projection algorithm.

Abstract: A device comprises an electric field applying assembly adapted to generate an electric field having a discrete electric field profile; a conducting volume and an electrical interface region provided between the conducting volume and the electric field applying assembly such that the discrete electric field is applied to the material by the electric field applying assembly at a location spaced from the conducting volume, wherein the electrical interface region comprises at least an ionically conductive material arranged adjacent to an in contact with the conducting volume; such that the discrete electric field applied by the electric field applying assembly is smoothed by the electrical interface region so that the electric field profile established within the conducting volume is substantially continuous.

Abstract: In an ion mobility separation device, there are problems that while arraying of separation electrodes and flow paths is restricted, time required for scanning correction voltages becomes longer and the throughput is reduced when the correction voltages are set in detail. These problems are solved for example by the following means.

Abstract: Particles of interest such as DNA, RNA may be detected in trace quantities by subjecting the particles to concentration by scodaphoresis, detecting a signal indicative of the presence of the particles in a scodaphoresis focus spot and performing phase-sensitive detection on the signal using a reference signal tied to the scodaphoresis fields. Specificity may be enhanced by using a medium having high affinity for the particles and/or markers having specific affinity for the target particles. In some embodiments a fluorescence signal is detected and subjected to phase-sensitive analysis. The signal may be detected by a camera or other imaging system.

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: Particles may be injected into a matrix for concentration by scodaphoresis using a quadrupole injection field. Particles may be injected from two or more sample chambers simultaneously. Particle injection may be performed simultaneously with performing scodaphoresis. In some embodiments the particles are concentrated into a well containing fluid. The well can extend out of a plane of the matrix. Altering the relative phases of components of a scodaphoresis field permits concentration of selected particles and exclusion of other particles. Scodaphoresis methods may be applied to DNA, other bio-molecules and other particles.

Abstract: Particles of interest, such as DNA molecules, are injected into a medium by applying a first field. Once in the medium the particles are concentrated by applying one or more fields that cause mobilities of the particles in the medium to vary in a manner that is correlated with motions of the particles. Particle injection and particle concentration may be performed concurrently or in alternation.

Abstract: Methods and apparatus providing improved fidelity and specificity when separating nucleic acids from a sample, but without need for amplification. In particular, using the disclosed methods, it is possible to isolate a variant nucleic acid (i.e., a mutation) from a non-target nucleic acid (i.e., a wild-type) when the variant is present in the original sample at a much lower concentration than the non-target, e.g., 1:10,000, without substantial loss of the variant.

Abstract: Methods and apparatus for separating, concentrating and/or detecting molecules based on differences in binding affinity to a probe are provided. The molecules may be differentially modified. The molecules may be differentially methylated nucleic acids. The methods can be used in fields such as epigenetics or oncology to selectively concentrate or detect the presence of specific biomolecules or differentially modified biomolecules, to provide diagnostics for disorders such as fetal genetic disorders, to detect biomarkers in cancer, organ failure, disease states, infection or the like.

Abstract: Methods and apparatus for moving and concentrating particles apply an alternating driving field and an alternating field that alters mobility of the particles. The driving field and mobility-varying field are correlated with one another. The methods and apparatus may be used to concentrate DNA or RNA in a medium, for example. Methods and apparatus for extracting particles from one medium into another involve applying an alternating driving field that causes net drift of the particles from the first medium into the second medium but no net drift of the particles in the second medium.

Abstract: Particles may be injected into a matrix for concentration by scodaphoresis using a quadrupole injection field. Particles may be injected from two or more sample chambers simultaneously. Particle injection may be performed simultaneously with performing scodaphoresis. In some embodiments the particles are concentrated into a well containing fluid. The well can extend out of a plane of the matrix. Altering the relative phases of components of a scodaphoresis field permits concentration of selected particles and exclusion of other particles. Scodaphoresis methods may be applied to DNA, other bio-molecules and other particles.

Abstract: Particles of interest, such as DNA molecules, are injected into a medium by applying a first field. Once in the medium the particles are concentrated by applying one or more fields that cause mobilities of the particles in the medium to vary in a manner that is correlated with motions of the particles. Particle injection and particle concentration may be performed concurrently or in alternation.

Abstract: Methods and apparatus for moving and concentrating particles apply an alternating driving field and an alternating field that alters mobility of the particles. The driving field and mobility-varying field are correlated with one another. The methods and apparatus may be used to concentrate DNA or RNA in a medium, for example. Methods and apparatus for extracting particles from one medium into another involve applying an alternating driving field that causes net drift of the particles from the first medium into the second medium but no net drift of the particles in the second medium.

Abstract: Methods of use, accessories and chambers, optimal for performing Pulsed Field Gel Electrophoresis (PFGE) of DNA molecules in ‘Contour Clamped Homogeneous Electric Field’ (CHEF) and ‘Transversal Alternating Field Electrophoresis’ (TAFE) systems, are provided herein. DNA molecules are rapidly separated in the minigels of these chambers. The sizes of chambers and accessories are determined by the separation between the opposite polarity electrodes; which is comprised between 6.2 and 15 cm. Reproducibility of molecule separation is achieved because the accessories warrant homogeneous electric resistance in the buffer and minigels. Chambers allow a high-throughput sample format using the reagents efficiently. It is attained excluding the non-useful electrophoresis zones. For a better optimization, TAFE chambers have several useful electrophoresis zones (UEZ), each carrying a minigel.

Abstract: A process for rapid typing of yeast, parasites and bacteria is provided. It comprises the following steps: a) Preparing immobilized intact DNA in 5 to 60 minutes aided by a method involving a reagent kit that only contains buffer solution, a detergent, a metal chelating agent and an agent to disrupt the hydrogen bonds. b) Separating intact DNA molecules or their restriction fragments in miniequipments for Pulsed Field Gel Electrophoresis of the CHEF (Contour Clamped Homogeneous Electric Field) and TAFE (Transversal Alternating Field Electrophoresis) systems in times comprised between 2.5 and 7 hours. c) Selecting the optimal conditions that should be set in miniCHEF with the aid of a method to simulate the electrophoresis patterns d) Providing reorientation times, migration velocities and sizes of the molecules calculated with the aid of a method to analyze the migrated distances without the use of size markers.

Abstract: A method and apparatus for fractionation of charged macro-molecules such as DNA is provided. DNA solution is loaded into a matrix including an array of obstacles. An alternating electric field having two different fields at different orientations is applied. The alternating electric field is asymmetric in that one field is stronger in duration or intensity than the other field, or is otherwise asymmetric. The DNA molecules are thereby fractionated according to site and are driven to a far side of the matrix where the fractionated DNA is recovered. The fractionating electric field can be used to load and recover the DNA to operate the process continuously.

Abstract: Embodiments of the present invention provide methods and devices for manipulating particles using dielectrophoresis. Insulating ridges and valleys are used to generate a spatially non-uniform electrical field. Particles may be concentrated, separated, or captured during bulk fluid flow in a channel having insulating ridges and valleys.

Abstract: Provided is a method for determining a zeta potential generated between a solid wall and a solution. The method includes (a) injecting an electrolyte solution into a first inlet of a T channel, which is provided with first and second inlet electrodes and a grounded outlet electrode, and a mixed solution of the electrolyte solution and a fluorescent dye into a second channel of the T channel and maintaining a steady-state of the two solutions; (b) applying a direct current electric field from the first and second electrodes to the outlet electrode to form an interface between the electrolyte solution and the mixed solution; (c) applying an alternating current electric field from one of the two inlet electrodes to the outlet electrode to oscillate the interface; and (d) measuring an amplitude of oscillation of the interface and determining the zeta potential from the standard relationship between the zeta potential and the amplitude.

Abstract: A microcapillary device includes a microcapillary tube. An anode is positioned at a first end of the microcapillary tube. A cathode is positioned at a second end of said microcapillary tube. A plurality of electric field reducing components are spaced apart along a length of the microcapillary tube. The anode and the cathode generate an electric field along the length of the microcapillary tube, and the plurality of electric field reducing components selectively reduce the electric field at spatial intervals along the length of the microcapillary tube.

Abstract: An electrophoretic cell configuration and related method are disclosed that employ oppositely directed traveling electrical waves. The waves travel across the cell and samples undergoing separation. Various strategies are used to selectively direct the movement and arrangement of the samples and resulting sample patterns.

Abstract: A method and system for controlling flow motion in a channel/cavity in a microfluidic system includes positioning at least one pair of electrodes in and/or proximate to the channel/cavity. A buffer solution is placed in the channel/cavity, the buffer solution having at least one dielectric property that varies in response to changes in temperature of the solution. An AC/DC voltage is applied to the electrodes to generate an electric field in the channel/cavity; the AC voltage having a known magnitude and frequency and the DC voltage having a known magnitude. The magnitude of the AC/DC voltage is adjusted to cause Joule heating of the buffer solution in the channel/cavity. The geometry and position of the electrodes is adjusted to generate a temperature gradient in the buffer solution, thereby causing a non-uniform distribution of the dielectric property within the solution in the channel/cavity. The dielectric non-uniformity produces a body force and flow in the solution.

Abstract: A sample load and injection device (10) includes sample introduction capillaries (11) attached to a microfluidic device (12). Sample introduction capillaries (11) are connected to sample introduction channels (18). Sample introduction capillaries (18) are connected to separation channels (20) at connection points (21). At a defined distance along the separation channels (20), auxilliary channels (23) originate at connection points (24). The sample load and injection device includes cover plate (28) which has connecting channels (26, 32). Connecting channel (26) is associated with ends (24) of sample introduction channels (18). Connecting channel (32) is associated with ends (20).

Abstract: A method and apparatus for fractionation of charged macro-molecules such as DNA is provided. DNA solution is loaded into a matrix including an array of obstacles. An alternating electric field having two different fields at different orientations is applied. The alternating electric field is asymmetric in that one field is stronger in duration or intensity than the other field, or is otherwise asymmetric. The DNA molecules are thereby fractionated according to site and are driven to a far side of the matrix where the fractionated DNA is recovered. The fractionating electric field can be used to load and recover the DNA to operate the process continuously.

Abstract: A fluidic channel patterned with a series of thin-film electrodes makes it possible to move and concentrate DNA in a fluid passing through the fluidic channel. The DNA has an inherent negative charge and by applying a voltage between adjacent electrodes the DNA is caused to move. By using a series of electrodes, when one electrode voltage or charge is made negative with respect to adjacent electrodes, the DNA is repelled away from this electrode and attached to a positive charged electrode of the series. By sequentially making the next electrode of the series negative, the DNA can be moved to and concentrated over the remaining positive electrodes.

Abstract: The invention provides a novel solution isoelectric focusing device and method that can reproducibly fractionate charged molecules into well-defined pools. This approach can be applied to mixtures of charged molecules, such as eukaryotic proteome samples where reproducible resolution and quantitation of greater than 10,000 protein components is feasible.

Abstract: Methods of use, accessories and chambers, optimal for performing Pulsed Field Gel Electrophoresis (PFGE) of DNA molecules in ‘Contour Clamped Homogeneous Electric Field’ (CHEF) and ‘Transversal Alternating Field Electrophoresis’ (TAFE) systems, are provided herein. DNA molecules are rapidly separated in the minigels of these chambers. The sizes of chambers and accessories are determined by the separation between the opposite polarity electrodes; which is comprised between 6, 2 and 15 cm. Reproducibility of molecule separation is achieved because the accessories warrant homogeneous electric resistance in the buffer and minigels. Chambers allow a high-throughput sample format using the reagents efficiently. It is attained excluding the non-useful electrophoresis zones For a better optimization, TAFE chambers have several useful electrophoresis zones (UEZ), each carrying a minigel.

Abstract: The invention provides a microfluidic apparatus for performing 2-D biomolecular separations. The microfluidic 2-D device may include first and second planar substrates which include at least a first dimension microchannel extending in a first direction and an array of second dimension microchannels extending in a second direction, preferably, orthogonal to the first dimension. The ends of at least some of the microchannels are in fluid communication with a plurality of reservoirs. The substrates may further include a number of microchannels and reservoirs. The reservoirs are in electrical communication with a plurality of electrodes and voltage power sources. The device enables two dimensional separations of proteins and other biomolecules. According to another aspect of the invention, an isoelectric point based separation is enabled in a first dimension, and a size based separation in a second dimension.

Abstract: Integrated systems, apparatus, software, and methods for performing biochemical analysis, including DNA sequencing, genomic screening, purification of nucleic acids and other biological components and drug screening are provided. Microfluidic devices, systems and methods for using these devices and systems for performing a wide variety of fluid operations are provided. The devices and systems of are used in performing fluid operations which require a large number of iterative, successive or parallel fluid manipulations, in a microscale, or sealed and readily automated format.

Abstract: A method is disclosed for moving, isolating and/or identifying particles in a sample by placing said sample in a spatially varying electrical field wherein the spatially varying electrical field is following a mathematical nonmonotonous function, selected from the group consisting of linear, hyperbolic, parabolic, parabolic functions or y˜xp/q and combinations thereof wherein p q means an integer. Also various devices are disclosed for performing the method.

Abstract: A means and method for indirect detection of constituent components of a mixture separated in a chemical separation process. Fluorescing ions are distributed across the area in which separation of the mixture will occur to provide a generally uniform background fluorescence intensity. For example, the mixture is comprised of one or more charged analytes which displace fluorescing ions where its constituent components separate to. Fluorescing ions of the same charge as the charged analyte components cause a displacement. The displacement results in the location of the separated components having a reduced fluorescence intensity to the remainder of the background. Detection of the lower fluorescence intensity areas can be visually, by photographic means and methods, or by automated laser scanning.

Abstract: A method and apparatus for carrying out electrophoretic separation is provided which imparts a fractal field component to the particles themselves or to the medium in which the particles are to be separated which, in combination with a steady field component, provides for a fast electrophoretic separation method that can be used on molecules and particles of a larger size than currently available electrophoretic methods.

Abstract: A method for determining the nucleotide size of DNA fragments separated by gel electrophoresis, comprising the steps of (i) measuring the migration time of each detected DNA fragment, and (ii) correlating the size of each detected DNA fragment with its migration time.

Abstract: Methods are provided for assaying electrophoretically separated components of sample in a gel. Following an initial separation phase of the sample components into distinct bands within separate zones of the gel, the separated components are held stationary on the gel in a hold mode. During the hold mode, reagent required for an intended assay is applied to the zone of the gel comprising the component to be assayed. The assay is conducted during the hold-mode. A wide range of assays can be conducted on the components in the gel, without the need for a blotting step. Following completion of the assay, the hold mode is removed and, if desired, the sample components are further separated in the gel.

Abstract: Electrophoresis apparatus with a gel support configured and arranged to hold a gel, a buffer chamber configured and arranged to hold a buffer, with the buffer contacting each end of the gel, and a buffer shaper configured to be positioned near the gel support and in contact with the buffer. The buffer shaper is positioned nearer to one portion of the gel support than to another portion of the gel support to cause the depth of buffer between the gel support and the buffer shaper to vary along the length or width of the gel support and buffer shaper.