Abstract: A capillary electrophoresis device including a capillary array, and a method of manufacturing the capillary array, are provided. During the manufacture of the capillary array, a plurality of capillaries are arranged in a substantially parallel arrangement and are fixed with a fixing member, to form a ribbon-shaped member. A detection cell can be arranged on the ribbon shaped member. The capillary array can achieve uniform heat dissipation thereby allowing electrophoretic velocity to be independent of the temperature characteristics of the capillaries. The plurality of capillaries are not attracted or repelled to each other by way electrostatic effects during electrophoresis, and the productivity of the capillary array can be improved.

Abstract: The object of the present invention is to provide a production process of a microfluidic device in which a porous resin layer, which is capable of optimally fixing a large amount of enzyme, antigen or other protein or catalyst on the inner surface of a minute channel of a microfluidic device without obstructing said channel, is formed at a uniform thickness on the surface of said channel. In the present invention, by preliminarily forming a porous resin layer having a large number of pores in its surface on a substrate, and forming an indentation having a porous resin layer on its bottom surface by using an activating energy beam-curable composition on said porous resin layer, followed by forming a channel by adhering a member serving as a cover to said indentation, a porous resin layer can easily be formed at a uniform thickness on the surface of said channel.

Abstract: Bubble-free electrodes, electrochemical cells including bubble-free electrodes, analytical devices, and methods for preparing and using them are provided. The analytical devices each include at least one bubble-free electrode. Analytical devices that include an electrochemical cell and a sample containment device are also provided, wherein the electrochemical cell includes an anodic reservoir, a cathodic reservoir, an electrical connection between the anodic reservoir and the cathodic reservoir, and a first bubble-free electrode disposed within one of the anodic reservoir and the cathodic reservoir. A second electrode is disposed within the other reservoir and a power source is provided having a positive terminal that is normally in electrical contact with the first electrode, and a negative terminal that is normally in electrical contact with the second electrode.

Abstract: The present invention provides an apparatus and method for threading a biopolymer through a nanopore. The apparatus of the present invention provides a substrate having a channel with a channel wall and a nanopore in the channel wall. The channel and nanopore are designed for receiving a biopolymer. The apparatus includes at least one set of electrodes for moving the biopolymer in a first direction past the nanopore, and at least one set of electrodes for moving the biopolymer through the nanopore in a second direction. The invention also provides a method for threading a biopolymer through a nanopore. The method includes moving the biopolymer past the nanopore in a first direction, and threading the biopolymer through the nanopore in a second direction.

Abstract: The present invention relates to an apparatus and methods of separating particles or cells according to their sizes, wherein the size of each of the particles or cells is characterized by a corresponding diameter. In one embodiment, the method includes the steps of providing a microchannel structure having at least one channel that is defined by a first sidewall and a second, opposite sidewall and has an insulating protrusion formed on one of the first sidewall and the second, opposite sidewall, introducing a plurality of particles or cells in a liquid medium into the at least one channel, and generating a non-uniform electrical field in the at least one channel such that when the plurality of particles or cells passes by the insulating protrusion, the plurality of particles or cells each receives a dielectrophoretic force proportional to its diameters, thereby being separable according to their sizes. The method further has the step of collecting particles or cells after the separation of particles or cells.

Abstract: A flow cytometer. In one embodiment the flow cytometer includes a microchannel structure adapted for transporting a fluid medium containing one or more types of particles; means for generating electrokinetically microfluidic flows to transport the fluid medium in the microchannel structure so as to differentiate the one or more types of particles of the fluid medium therein; and an optical detection system coupled with the microchannel structure for detecting the differentiated one or more types of particles of the fluid medium.

Abstract: The present invention is a capillary electrophoresis device, comprising a substrate; a first channel in the substrate, and having a buffer arm and a detection arm; a second channel in the substrate intersecting the first channel, and having a sample arm and a waste arm; a buffer reservoir in fluid communication with the buffer arm; a waste reservoir in fluid communication with the waste arm; a sample reservoir in fluid communication with the sample arm; and a detection reservoir in fluid communication with the detection arm. The detection arm and the buffer arm are of substantially equal length.

Abstract: A system and method for capillary electrophoresis are provided for analyzing a macromolecule prepared from a complex liquid mixture. In particular applications, methods and apparatus are provided for separating and analyzing a solution containing a denatured macromolecule by employing a stationary capillary electrophoresis apparatus. An apparatus for capillary electrophoresis includes an inlet chamber and a capillary electrophoresis column. One end of the column is fixed at the interior of the inlet chamber. The column has a length of at least about 20 centimeters. Also included is a liquid source adapted for automatic control. The liquid source supplies a liquid sample through an input valve into the inlet chamber so that the sample is in fluid communication with the end of the column. A method for capillary electrophoresis includes automatically supplying the liquid sample to the apparatus.

Abstract: A plurality of types of liquid with different electrical conductivity flow through a micro channel having a plurality of channels. When an electric field is applied thereto, an electrokinetic driving flow generated in the micro channel attracts objective submicron particles to one side. Therefore, the particles are completely separated in a single operation by use of the micro channel having extremely simple structure, without the necessity of special machining of the channels and the like.

Abstract: An electrophoresis apparatus 1 has an introducing passage 11 for allowing a sample to move from one end of the introducing passage 11 toward the other end thereof, and an analyzing passage 10, formed so as to cross the introducing passage in a cross-portion 8, for allowing a part of the sample in the cross-portion 8 to be separated from the other part of the sample in the introducing passage 11 to move by electrophoresis, wherein the angle between a downstream portion 10a of the analyzing passage 10 from the cross-portion 8 in an electrophoresis direction, and at least one of an upstream portion of the introducing passage 11 from the cross-portion 8 in a sample moving direction, and a downstream portion of the introducing passage 11 from the cross-portion 8 in the sample moving direction, is an acute angle.

Abstract: Analysis is performed efficiently in an electrophoresis apparatus while avoiding deterioration of samples. A plurality of sample plates are stored in frozen storage. When a particular sample plate is being analyzed, other sample plates are stored in a standby unit. In this way, a plurality of sample plates can be stored under cool conditions and analysis can be performed efficiently.

Abstract: A capillary electrophoresis apparatus capable of efficiently using a polymer in a polymer container is provided. The present invention relates to a mechanism for efficiently using the polymer in the polymer container in a capillary electrophoresis apparatus for the electrophoresis with a separation medium filled in a capillary. According to the present invention, since the polymer in the polymer container is not contacted with the air, deterioration of the polymer by oxidation can be prevented.

Abstract: Liquid-keeping part is formed in channel 107 of chip 111 for electrophoresis. Electrophoresis is carded out by using electrophoresis chamber 118 holding chip 111 for electrophoresis in its inside and having a system of controlling temperature of electrophoretic chip 111 by putting humidity-controlling liquid 117.

Abstract: In general, the present invention provides microfluidic devices comprised of polymer coatings with triggerable analyte capture moieties. In some embodiments, a microfluidic device is provided, useful in electrophoresis, and is comprised of at least one separation channel with a surface, such as but not necessarily an inner surface, and having a polymer coating introduced onto the surface. The polymer coating is comprised of moieties capable of being triggered to immobilize analytes to the surface.

Abstract: The analysis apparatus for microchips, each at least having a main flow path performing migration of a sample for analysis inside a sheet-like member, comprises a holding part holding microchips so that the multiple main flow paths are provided; a pretreatment part common to the multiple main flow paths for performing a pretreatment step prior to an analysis step in each of the multiple main flow paths; a processing part for performing analysis in each of the main flow paths independently of the others; and a control part controlling an operation in the pretreatment part so that when a pretreatment step for one main flow path ends, a pretreatment for a next main flow path starts and further controlling an operation in the processing part so that an analysis is subsequently performed for the main flow path where the pretreatment step has ended.

Abstract: There is provided a flow cell assembly in which a shuttle supports and positions a capillary with its end extending beyond the shuttle. The flow cell assembly facilitates the replacement of a flow cell which is damaged or with flow cells having capillaries of different size or shape.

Abstract: A method of electrophoresis, an electrophoresis apparatus and a capillary array in which a fluorescently labelled sample is supplied into capillaries in a capillary array constituted by a plurality of capillaries and including a sample supply portion, an electrophoresis medium supply portion and a detection portion while controlling the temperature of the capillary array through gas circulation, the sample is caused to migrate and separated in the capillaries through electrophoresis, and at the region where the capillaries are contacted or come close each other a plurality of capillaries are contacted to a solid body so as to dissipate heat generated from the capillaries to the solid body.

Abstract: Polymeric surfactants (molecular micelles) are disclosed for use in open tubular capillary electrochromatography or in high performance liquid chromatography. For example, fused silica capillaries are coated with thin films of charged polymers in a polyelectrolyte multilayer (PEM). A PEM coating may be formed in situ by alternate rinses with positive and negative polyelectrolytes. At least the innermost of the negatively charged polymer layers is a molecular micelle. Prototype embodiments have successfully separated seven benzodiazepines from one another. The run-to-run, day-to-day, week-to-week and capillary-to-capillary reproducibilities were very good, with relative standard deviation values less than 0.01. The PEM-coated capillary was very robust over at least 200 runs. Stability against high and low pH values was also observed. Using chiral polymerized micelles, chiral separations may be achieved, as was demonstrated with a separation of the enantiomers of 1,1?-binaphthyl-2,2?-dihydrogenphosphate.

Abstract: A micropump utilizes electrically controlled interfacial tension between a mercury column and an electrolyte solution in a capillary tube, and also uses the gas pressure in a confined chamber connected to the capillary tube as the restoring pressure. Accordingly, the pump operates without generating external jitter or noise, in vertical, horizontal, or in any orientation against the gravitational force. In this manner, the flow rate of the pumped fluid can be widely and conveniently controlled. Further, the micropump is small in size and simple in construction, and needs extremely small power consumption.

Abstract: The present invention provides an on-chip packed reactor bed design that allows for an effective exchange of packing materials such as beads at a miniaturized level. In accordance with the present invention, there is provided a method of concentrating an analyte within a microfluidic analysis system, comprising the steps of: a) providing a main channel having a trapping zone suitable for trapping packing material; b) providing a slurry of a reagent treated packing material prepared in a solution having a predetermined composition of a solvent; c) inducing a flow of said packing material into said trapping zone through a flow channel connected to said trapping zone so as to load said trapping zone and form a packed bed of said packing material; d) and flowing a sample containing analytes through said packed bed, said reagent acting to concentrate at least some of said analytes within said trapping zone.

Abstract: An apparatus for controlling the flow rate of a fluid passing through a micro-flow path, comprising an electrode layer, an electrolyte layer and a conductive polymer membrane in this order, the conductive polymer membrane being exposed to the micro-flow path, and the flow rate being controlled by supplying electric current from the electrode layer to the conductive polymer membrane via the electrolyte layer.

Abstract: A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either ionic current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to a variety of processes, including electrokinetically induced pressure flow in a region of a microchannel that is not influenced by an electric field, sample concentration enhancement and injection, as well as improving the analysis of materials where it is desired to eliminate electrophoretic bias. Other applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

Abstract: The invention concerns to an electrophoretic separation device comprising a separation channel having at least one in- and outlet opening at the beginning and at the end of the channel and one electrode in the region of the inlet opening and one electrode in the region of the outlet opening. As well the invention concerns to a method for electrophoretic separation. The invention is characterized in that said separation channel is subdivided into at least two sections in series being coupled mutually by a joint providing an electrical connection means having a ion-conductive material separating said channel from a reservoir being apart the channel and provided with an electrode.

Abstract: A microdevice is constructed from a substrate having a microchannel formed therein and a cover plate arranged over the substrate. The cover plate in combination with the microchannel at least partially defines a conduit within the microdevice. The conduit has a surface that extends from an upstream region toward a downstream region and terminates at an opening. The microdevice also includes an annular lining that conforms to the conduit surface at the downstream region and extends from the opening toward the upstream region in the conduit. An emitter may be produced in situ by depositing an emitter material on the annular lining. In addition, material may be removed from the cover plate and/or substrate about the opening. As a result, an exterior microdevice surface is formed and a downstream portion of the emitter is exposed that protrudes from the exterior surface.

Abstract: A system, method and apparatus employing the laminar nature of fluid flows in microfluidic flow devices in separating, sorting or filtering colloidal and/or cellular particles from a suspension in a microfluidic flow device is disclosed. The microfluidic flow device provides for separating a particle within a suspension flow in a microfluidic flow chamber. The chamber includes a microfluidic channel comprising at least one inlet port for receiving a suspension flow under laminar conditions, a first outlet port and a second outlet port. The chamber further includes an interface for translating a particle within the channel. The first outlet port receives a first portion of the suspension exiting the said channel and the second outlet port receives the particle in a second portion of the suspension exiting the channel.

Abstract: Described is a fluidic microsystem with at least one compartment for the receiving and/or the through-flow of a liquid and having an electrode arrangement with a multiplicity of electrodes, between which a coaction zone is established, whereby the compartment possesses at least one wall, through which electromagnetic radiation can be linked into the said coaction zone in accord with a predetermined incident direction, and on at least one electrode a cooling apparatus is provided, and on which at least one respective electrode at least one reflector layer is provided, and wherein the respective electrode is at least partially shielded in reference to the incident beam direction, and having at least one heat conducting layer by means of which the respective electrode stands in thermal communication with a wall of the compartment, and/or includes an active cooling element, which is placed in thermal contact with the respective electrode.

Abstract: Fluidic flow is directed in a capillary or channel in a miniaturized separation or microfluidic device by the addition of liquid crystals to the fluid filling the channel. The liquid crystal medium undergoes changes in morphology upon the addition of external stimuli (magnetic and/or electric field and temperature). Under appropriate conditions this externally triggered change in liquid crystal produces a change in viscosity. This triggered change in viscosity directs fluid flow in multiple path channels and/or capillaries and therefore serves as a means of directing and controlling fluid flow within a capillary or channel in a miniaturized separation or microfluidic device.

Abstract: Disclosed is a method and apparatus by which a sample can be taken from a process and be analyzed on-line by means of a capillary electrophoresis apparatus. On the feed side of the capillary electrophoresis unit (13) the sample is continuously collected via a duct (16) from the process into the sample feeding system and fed into the capillary ducts (2, 3) through the same duct as is the feed solution, and all the solutions (16, 17, 18, 19) both on the feed side and on the exit end of the capillary electrophoresis unit (13) are pumped through the flow ducts, and the liquids flown through the capillary are removed on the exit end of the capillary electrophoresis unit (13) by means of a liquid treatment system.

Abstract: In accordance with the present invention, stable electroosmotic flow systems and methods for designing the same are disclosed. The invention provides electroosmotic flow systems comprising electroosmotic flow elements, including bridge elements, that have matching flux ratios, i.e., when two or more elements of an electroosmotic flow system are in fluidic and electrical communication at a junction, the flux ratio for each of the elements is selected so that the difference in flux ratios system adjacent two elements is less than a target value. The invention also provides methods for designing such systems.

Abstract: The invention herein provides improved sample injection systems and related methods to create microfluidic devices with symmetrical channel configurations that can produce relatively large sample volumes. An embodiment of the invention provides microfluidic structures with different geometries that are symmetrical from the perspective of a sample load channel and a sample waste channel, which essentially eliminates issues of time offset and other problems commonly associated with twin-T sample formation techniques. A split-injection approach and related methods of sample plug formation are therefore provided.

Abstract: An electrophoresis apparatus is provided in which negative effects caused by abnormalities in a current-carrying path in an electrophoresis apparatus can be avoided or reduced. The current flowing in the current-carrying path during electrophoresis can be measured to detect the state of a separating medium, and the application of a voltage to the current-carrying path can be interrupted.

Abstract: An object of the present invention is to provide a capillary electrophoresis apparatus in which simultaneity can be ensured between sensitivity and data acquisition to decrease a pull-up signal while spectral data acquisition is eliminated in each capillary exchange. The invention relates to a capillary electrophoresis apparatus characterized in that a multi-bandpass filter is provided in an optical detection system. In one aspect of the invention, a signal detection area of a two-dimensional detector is divided into plural regions corresponding to wavelength transmission regions of the multi-bandpass filter. An integrated value of the fluorescence spectrum signal is determined in the region including a fluorescence spectrum peak of an analysis sample in the plural regions. The analysis is performed with the integrated value.

Abstract: An object of the present invention is to provide a capillary electrophoresis apparatus in which simultaneity can be ensured between sensitivity and data acquisition to decrease a pull-up signal while spectral data acquisition is eliminated in each capillary exchange. The invention relates to a capillary electrophoresis apparatus in which capillary position shift is detected in each capillary exchange by detecting a capillary position. A capillary position measuring light source is provided in the capillary electrophoresis apparatus of the invention. The capillary is irradiated with light emitted from the capillary position measuring light source, a capillary image is detected with a two-dimensional detector, and thereby a position deviation of the capillary is determined. On the basis of the position deviation of the capillary, a data acquisition area is set in the two-dimensional detector, or a reference fluorescent light spectrum determined from the capillary at the standard position is corrected.

Abstract: An electrophoresis apparatus is provided with a plate 10 on which channels 110 are formed, a tray 22 on which the plate is to be set, a tray driving means 20 for rotary driving the tray 22 on which the plate is set, a voltage application means 30 for applying voltage to a buffer agent in the channels on the plate 10, an optical detection part for irradiating the channels on the plate with light, and detecting fluorescence that is generated from the sample due to the light irradiation, and a plate clamp 35 for pressing the plate 10 at only the channel formation areas of the plate 10 against the plate setting surface of the tray 22, there fixing and holding the plate 10 on the plate setting surface of the tray 22. Therefore, it is possible to prove a compact, light, and inexpensive electrophoresis apparatus which does not require complicated preparation works, and provides results accurately in short time.

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 method for conducting a broad range of biochemical analyses or manipulations on a series of nano- to subnanoliter reaction volumes and an apparatus for carrying out the same are disclosed. The invention is implemented on a fluidic microchip to provide high serial throughput. In particular, the disclosed device is a microfabricated channel device that can manipulate nanoliter or subnanoliter reaction volumes in a controlled manner to produce results at rates of 1 to 10 Hz per channel. The reaction volumes are manipulated in serial fashion analogous to a digital shift register. The invention has application to such problems as screening molecular or cellular targets using single beads from split-synthesis combinatorial libraries, screening single cells for RNA or protein expression, genetic diagnostic screening at the single cell level, or performing single cell signal transduction studies.

Abstract: An electrokinetic pump achieves high and low flow rates without producing significant gaseous byproducts and without significant evolution of the pump fluid. A first feature of the pump is that the electrodes in the pump are capacitive with a capacitance of at least 10?4 Farads/cm2. A second feature of the pump is that it is configured to maximize the potential across the porous dielectric material. The pump can have either or both features.

Abstract: A capillary electrophoresis system includes a plurality of capillaries arranged in parallel on a vertical plane at an identical distance from each other, each of which has a sample injection end immersed in a cathode buffer 23 and pointed downward vertically to facilitate connection between the cathode buffer 23 and a sample solution. The sample elution end is connected via a pump block 11 and a connection tube 3 to an anode buffer 24. The height is made identical between the liquid levels for buffers 23 and 24 to prevent movement of the separation medium in the capillaries. The sample introduced from the sample injection end 20 moves upward vertically via electrophoresis to the sample elution end in the capillary and is passed through and detected at the fluorescence detection position 19. The effective separation length is thus decreased to 10 cm or less to attain high throughput.

Abstract: In the present capillary electrokinetic chromatograpy method, analytes are injected by electroosmotic flow directly from a sample matrix into a separation buffer containing an electrokinetic vector with an opposite mobility. Analytes can now be injected at the velocity of electroosmotic flow, but are retained at the interface of the sample matrix-co-ion and separation buffer micelle zones as analyte/micelle complexes. Manipulation of the injecting force and opposing stacking force allow greatly increased length or volume of injection. Concentrations of the micelle, methanol, and borate in the separation buffer were provided to increase maximum injection length of neutral analytes. Reducing the analyte velocity in the separation buffer without substantially decreasing the velocity of the analyte during injection from the sample vial allowed greatly extended sample plug injection lengths. It is further enabled to inject sample solvent volumes equivalent to about twenty times the effective capillary volume.

Abstract: A method of, and apparatus for, automatically determining an electric charge—related characteristic or derived parameter of particles in a dispersion or of a cell wall, comprises having a particle—containing dispersion provided in a cell. The dispersion is illuminated with light from a light source and detecting from a detection volume light scattered from the particles. An electric field is applied to the dispersion at a first frequency of change of direction of the electric field and an electric field is subsequently applied to the dispersion at a second frequency of change of direction of the electric field. First signals detected from the scattered light when the first frequency electric field is applied are used to provide first values related to the velocity distribution of the particles.

Abstract: The invention provides a microfabricated device for sorting cells based on a desired characteristic, for example, reporter-labeled cells can be sorted by the presence or level of reporter on the cells. The device includes a chip having a substrate into which is microfabricated at least one analysis unit. Each analysis unit includes a main channel, having a sample inlet channel, typically at one end, and a detection region along a portion of its length. Adjacent and downstream from the detection region, the main channel has a discrimination region or branch point leading to at least two branch channels. The analysis unit may further include additional inlet channels, detection points, branch points, and branch channels as desired. A stream containing cells is passed through the detection region, such that on average one cell occupies the detection region at a given time.

Abstract: A capillary electrophoresis device as well as a process for fabrication of the device is disclosed. The capillary electrophoresis device comprises a device body structure having a plurality of reservoirs arrayed thereon for loading a sample, and a plurality of rows of grooves transversely defined to be connected with the reservoirs for receiving at least a capillary electrophoresis chip. The capillary electrophoresis chip comprises a straight main separation channel, an injection channel, and a plurality of sample transport channels defined thereon in liquid communication with the reservoirs. After an electrode means is applied, the sample can be transported into the separation channel for detection and analysis.

Abstract: A method of simply controlling the flow of fluid in a micro system without using a complicated value structure, comprising the steps of adding the substance transformed from sol-gel by stimulation to the fluid flowing through the micro flow passage of the micro system, and adding the stimulation to the fluid at a desired position on the micro flow passage to transform the fluid into gel for flow control.

Abstract: Methods and compositions for modifying the surface of a polymeric substrate are provided. In the subject methods, at least a portion of the surface of the polymeric substrate is contacted with a biofouling resistant surfactant composition. At least a portion of the surfactant molecules of the composition are end modified with a non-reactive, charged end group that is charge stable over a pH range of about 2 to 12. The subject methods and compositions find particular use with electrophoretic devices, such as capillary electrophoretic devices.

Abstract: An electrode plate of a sample plate is set on the body of an electrophoretic apparatus, while a plug is inserted into a migration high voltage line connection hole and connected to a high-tension distribution cable. Each well of a base plate is inserted into a through hole of a well guide and further press-fit and engaged into a cavity of an electrode plate, for fixing the base plate to the electrode plate. Thereafter a sample is introduced into each well of the base plate and an end of a capillary column is dipped into each well for applying a migration voltage and electrophoretically injecting the sample into the capillary column.

Abstract: A sample handling system in a multi-channel capillary electrophoresis apparatus is disclosed. The sample handling system includes a work surface for supporting a plurality of samples located at a plurality of work surface coordinates and a sample loading assembly comprising a plurality of loading wells. At least one of the loading wells includes a capillary fixedly positioned therein. The system further includes a programmable sample transfer device for automatically transferring a sample from a work surface coordinate to a loading well. The invention further includes methods for using the sample handling system.

Abstract: A capillary array capable of being easily mounted on an electrophoresis apparatus without damaging the capillaries. The capillary array can include a plurality of capillaries that can be fixed via hollow electrodes on a load header in a matrix arrangement. The load header can be disposed on the electrophoresis apparatus. The capillary array can include a capillary frame onto which a capillary head and a detection portion can be detachably mounted. The structure allows the load header, the capillary head, the detection unit and other portions of the capillary array to be handled as a unit, thereby making it easier to mount the capillary array on the electrophoresis apparatus.

Abstract: The present invention is directed to methods of controlling the flow of fluids through a microfluidic circuit and, more particularly, to methods of controlling the movement of fluid through a microfluidic circuit using one or more triggerable passive valves. In one embodiment of a method of controlling the flow of fluids through a microfluidic circuit according to the present invention, the microfluidic circuit includes a triggerable valve in series with a passive valve. In a further embodiment of a method of controlling the flow of fluids through a microfluidic circuit according to the present invention, the microfluidic circuit includes first and second triggerable valves in parallel.

Abstract: An electrophoresis apparatus is generally disclosed for sequentially analyzing a single sample or multiple samples having one or more analytes in high or low concentrations. The apparatus comprises a relatively large-bore transport capillary which intersects with a plurality of small-bore separation capillaries. Analyte concentrators, having antibody-specific (or related affinity) chemistries, are stationed at the respective intersections of the transport capillary and separation capillaries to bind one or more analytes of interest. The apparatus allows the performance of two or more dimensions for the optimal separation of analytes.

Abstract: The present invention relates to methods and devices for separating particles according to size. More specifically, the present invention relates to a microfluidic method and device for the separation of particles according to size using an array comprising a network of gaps, wherein the field flux from each gap divides unequally into subsequent gaps. In one embodiment, the array comprises an ordered array of obstacles in a microfluidic channel, in which the obstacle array is asymmetric with respect to the direction of an applied field.