Abstract: Apparatus and a method are described for investigating polymorphs of a material, isomers of a material which allow different isomeric forms to be resolved, different hydrates/solvates and/or different salts of a material. The apparatus comprises an assembly (2) of reactor devices (6) arranged within a reactor body (8) which incorporates a heating/cooling block (10) and a stirrer block (12). A vessel support block (14) supports respective sample vessels (15) below each reactor device (6) for recieving material from the reactor devices. The apparatus includes a control unit (4) which includes a computer (16) which controls a robot for delivering materials to the reactor devices; a heating/cooling unit (18); a stirrer control unit (20); and a pressure unit (22) which controls the passage of material from the reactor devices (6) to the sample vessels (15).

Abstract: The invention relates to a microfabricated device and methods of using the device for analyzing and sorting polynucleotide molecules by size.

Abstract: A device for processing a biological sample includes a processing unit having at least one opening to receive a sample vessel and a plurality of processing stations positioned along the opening. The processing stations each have a compression member adapted to compress the sample vessel within the opening and thereby move a substance within the sample vessel among the processing stations. An energy transfer element can be coupled to one or more of the processing stations for transferring thermal energy to the content at a processing station.

Abstract: The invention is related to methods and apparatus that manipulate droplets in a microfluidic environment. Advantageously, embodiments of the invention manipulate droplets by controlling the electro-wetting characteristics of a surface with light, thereby inducing a gradient in the surface tension of a droplet. The gradient in the surface tension propels the droplet by capillary force. A variety of operations, such as transporting, joining, cutting, and creating can be performed. Advantageously, embodiments of the invention obviate the need to create a relatively large and complex control electrode array. A plurality of photoconductive cells or a layer of a photoconductive material selectively couples an electrode carrying an electrical bias to otherwise floating conductive cells in response to a beam of light. The electrical bias applied to the conductive cell generates a localized electric field, which can change the contact angle of the droplet, thereby permitting the droplet to be propelled.

Abstract: To investigate the flowability of a physiological fluid sample, an uptake passage (12) for the fluid sample (16), an actuator device (18) for the cyclic change in orientation of measuring particles (14) in the fluid sample (16), and a detector device (20, 22) for the preferably optical detection of the change in orientation of the measuring particles (14) are provided. In order to make reliable measurements possible with minimal instrument expense, it is proposed that the actuator device is formed by a pump unit (18) to produce a flow of the fluid sample (16) that travels back and forth along the uptake passage (12) and indicates the change in orientation of the measuring particles (14).

Abstract: The present invention provides microfluidic devices, systems and methods for using the same, which facilitate the introduction of fluid to and from a microfluidic channel located within the microfluidic devices.

Abstract: The present invention is directed to a system for filling sample chambers with liquid. The system includes a substrate defining the sample chambers and having a fill port, and a network of passageways connecting the sample chambers to the fill port. The system also includes a substrate support to retain the substrate in a fill position and a valve module on the substrate support. The valve module has a fill port seal opening to connect with the fill port of the substrate in the fill position, and a vacuum opening for connection to a source of vacuum. The system further includes a valve body having a liquid outlet port and a vacuum port, and means for operating the valve body so that the liquid outlet port and the vacuum port are alternately in fluid communication with the fill port seal opening.

Abstract: A microfluidics device includes a plurality of interaction cells and fluid control means including i) means for providing to the interaction cells a preparation fluid, and ii) means for providing to the interaction cells a sample fluid, wherein each interaction cell receives a different sample fluid. A plurality of microcantilevers may be disposed in each of the interaction cells, wherein each of the plurality of microcantilevers configured to deflect in response to an interaction involving a component of the sample fluid.

Abstract: A process and apparatus for rapidly screening materials using, for example, mass spectrometry has been developed. More specifically, an array of materials on a fluid permeable support contained within a reaction cell having a semipermeable membrane can be rapidly screened for characteristics such as catalytic activity, selectivity, and adsorption and desorption properties.

Abstract: Improved microfluidic devices, systems, and methods allow selective transportation of fluids within microfluidic channels of a microfluidic network by applying, controlling, and varying pressures at a plurality of reservoirs. Modeling the microfluidic network as a series of nodes connected together by channel segments and determining the flow resistance characteristics of the channel segments may allow calculation of fluid flows through the channel segments resulting from a given pressure configuration at the reservoirs. To effect a desired flow within a particular channel or series of channels, reservoir pressures may be identified using the network model. Viscometers or other flow sensors may measure flow characteristics within the channels, and the measured flow characteristics can be used to calculate pressures to generate a desired flow. Multi-reservoir pressure modulator and pressure controller systems can optionally be used in conjunction with electrokinetic or other fluid transport mechanisms.

Abstract: The movement and mixing of microdroplets through microchannels is described employing microscale devices, comprising microdroplet transport channels, reaction regions, electrophoresis modules, and radiation detectors. The discrete droplets are differentially heated and propelled through etched channels. Electronic components are fabricated on the same substrate material, allowing sensors and controlling circuitry to be incorporated in the same device.

Abstract: A device for placement of effluent comprises a substrate positioner, a deposition conduit, and a conduit positioner. The substrate positioner supports and positions a substrate on which effluent exiting from the deposition conduit is to be deposited. The conduit positioner moves an exit end of the deposition conduit relative to the substrate.

Abstract: A system for the rapid characterization of multi-analyte fluids, in one embodiment, includes a light source, a sensor array, and a detector. The sensor array is formed from a supporting member into which a plurality of cavities may be formed. A series of chemically sensitive particles are, in one embodiment positioned within the cavities. The particles may be configured to produce a signal when a receptor coupled to the particle interacts with the analyte. Using pattern recognition techniques, the analytes within a multi-analyte fluid may be characterized.

Abstract: Improved sealing for microstructures in microfluidic devices having a plurality of units is provided by providing collars surrounding the openings to the microstructures, such as reservoirs. The collars are protrusions extending from the surface of the devices and the internal walls of the collars generally aligned with the internal walls of the microstructure. Conformable and/or adhesive lids are employed for sealing the microstructures.

Abstract: An injection pump assembly 10 in a chemical delivery system for simultaneously delivering reagents into a combinatorial reactor system having multiple injectors. The assembly 10 has a plurality of injectors 12, each injector 12 being in fluid communication with one of the multiple reactors. Each injector 12 has (1) a pump 14 in which a plunger 18 sealingly moves to ingest, store and discharge a flushing solvent 20; (2) a pipette assembly 22 for loading, storing, and discharging one or more reagents into one of the reactors in the combinatorial reactor system, first and second reservoirs for retaining some of the reagents; (3) one or more hollow needles 32, each for selectively delivering a reagent 24 to the first 28 or the second 24 reservoir; (4) a first valve 34 positioned downstream of the first 28 reservoir; and (5) a second valve 36 positioned downstream of the second 30 reservoir. When each valve 34, 36 is in a closed position, the reagents 24, 48 can be stored in isolation from each other.

Abstract: This invention relates to a novel microfluidic device and methods of using this device to conduct in vitro studies on the reaction and effects of various compounds on cells. More particularly, it relates to a method for using stop flow in a microfluidic system to study the effect of compounds on individual cells. It also provides a method for observing the effects of candidate compounds on leukocyte rolling.

Abstract: A high throughput chemical handling system includes a chemical storage module, a transport module, and one or more liquid handling modules. The transport module may implement parallel chemical transport, and the system may include a plurality of asynchronously operable liquid handling modules coupled to the parallel transport module.

Abstract: The present invention, provides a flow cytometry apparatus for the detection of particles from a plurality of samples comprising: means for moving a plurality of samples comprising particles from a plurality of respective source wells into a fluid flow stream; means for introducing a separation gas between each of the plurality of samples in the fluid flow stream; and means for selectively analyzing each of the plurality of samples for the particles. The present invention also provides a flow cytometry method employing such an apparatus.

Abstract: A method and apparatus for the automation of existing medical diagnostic tests is described. This method, called sequential injection analysis, makes use of a pump, multi-position selection valve, and micro-bore tubing to automate sample manipulation and reagent addition. A suitable detector with a flow cell also forms part of the flow manifold and this detector is used to measure some parameter that can be related to the desired diagnostic measurement. A reagent cartridge suitable for storing and reconstituting lyophilized reagent or reagent concentrate is also described. Use of such a reagent cartridge further enhances the automation of the device by providing a means for preparing reagents in an automated fashion. Automation of the measurement sequence and the sequencing of tests are controlled by a suitable central processor unit and software. The apparatus provides a means of automating existing manual diagnostic tests and as yet, undefined tests.

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: The present invention, provides a flow cytometry apparatus for the detection of particles from a plurality of samples comprising: means for moving a plurality of samples comprising particles from a plurality of respective source wells into a fluid flow stream; means for introducing a separation gas between each of the plurality of samples in the fluid flow stream; and means for selectively analyzing each of the plurality of samples for the particles. The present invention also provides a flow cytometry method employing such an apparatus.

Abstract: Fixed volumes of samples are metered into the reaction channel of a microfluidic device using one or more slidable blocks having at least one fixed-length sample metering channel. In another aspect of the present invention, fixed volumes of samples are metered into the reaction channel using one or more slidable blocks having at least one fixed-length sample metering channel. In another aspect of the present invention, a sample injection scheme based on injection time is implemented using relatively sliding blocks of separation channels and sample channels. In a further aspect of the present invention, separation channels are configured in relation to the slidable block in a manner that enables separations to be conducted continuously for high-throughput assays.

Abstract: A method and apparatus for controlling a stream of liquid and air segments wherein the liquid and air segments are selectively aspirated into a first fluid conduit in a plurality of cycles, each cycle beginning with the aspiration of a first air segment and ending with the aspiration of a final air segment. The liquid and air segments are then transferred from the first fluid conduit to a second fluid conduit. The volume of the final air segment of each cycle is then adjusted after the final air segment has moved into the second fluid conduit. Next, the liquid segments and the air segments of each cycle are transferred from the second fluid conduit to a third fluid conduit. The volume of the first air segment of each cycle is then adjusted after the first air segment has moved into the third fluid conduit.

Abstract: Method intended for continuous detection and control of hydrate formation at any point of a pipe carrying multiphase petroleum fluids. The method uses a compositional code allowing to simulate the circulation modes and conditions at any point of the pipe, considering that the fluid mixture is substantially continuously at equilibrium, that the composition of the multiphase mixture is variable all along the pipe and that the mass of each constituent of the mixture is globally defined by a mass conservation equation regardless of its phase state. The thermodynamic hydrate formation conditions are detected after a particular stage of grouping the petroleum fluids into pseudo-components so as to isolate the hydrate forming components, with definition for each one of a mass fraction and of a certain number of characteristic physical quantities, and the data relative to these particular fractions are applied to the modules so as to determine at any point the hydrate dissociation temperature (Td).

Abstract: Apparatuses and methods are described for parallel oligonucleotide synthesis of hundreds of different sequences and lengths at a time. Standard phosphoramidite chemistry is employed. The syntheses take place in a reaction plate compatible with the industrial standard microplate format to allow the use of readily available automated instruments for subsequent processing. Key parameters in reducing synthesis volume in small reaction wells are discussed. This invention provides solutions to the difficulties of low volume, high number synthetic reactions.

Abstract: A device for preparing a radioactive water solution to be infused in a patient includes a reaction chamber (13) in which radioactive water vapour is formed by the catalysed reaction of oxygen gas containing oxygen-15 and hydrogen gas. A diffusion chamber (14) is provided which allows the radioactive water to penetrate, but which prevents the penetration of gasses. Tubes (26) and valves (16, 18) direct a sterile saline solution to the diffusion chamber (14), and then direct the saline solution containing radioactive water out from the diffusion chamber to a patient, or to a decay coil (22) being a part of the device. A measuring instrument is provided for measuring the radioactivity of the radioactive solution. The device is characterized in that the diffusion chamber (14), the tubes (26) the valves (16, 18), the radioactivity measuring instrument (17), and preferably also the reaction chamber 913), are mounted in the same frame 50, whereby they form a separate unit i.e.

Abstract: An automated in situ heat induced antigen recovery and staining method and apparatus for treating a plurality of microscope slides. The process of heat induced antigen recovery and the process of staining the biological sample on the microscope slide are conducted in the same apparatus, wherein the microscope slides do not need to by physically removed from one apparatus to another. Each treatment step occurs within the same reaction compartment. The reaction conditions of each reaction compartment for treating a slide can preferably be controlled independently, including the individualized application of reagents to each slide and the individualized treatment of each slide. The reagents are preferably held in a reagent dispensing strip similar to a “blister pack”.

Abstract: A fluid management apparatus includes a substrate having a first surface and a second surface opposite to the first surface. A plurality of fluid inlets, which are preferably media reservoirs, are formed in a first pattern in the first surface of the substrate. A plurality of fluid outlets, which are preferably nozzles, are arranged in a second pattern, which is different from the first pattern, in the second surface of the substrate. A plurality of fluid ducts formed in the substrate for connecting respective fluid inlets with respective fluid outlets are provided so that a format conversation from the fluid inlets to the fluid outlets is effected. The fluid outlets have opening cross-sections smaller than that of the fluid inlets. Furthermore, the fluid inlets may be arranged in the raster scheme of microtiter plates.

Abstract: A chemical analyzer for measuring a concentration of components of a sample liquid, by mixing the sample liquid with reagents, so as to react the reagents upon the components thereof, includes a carrier having an introducing portion through which the sample liquid is injected, passages for distributing the sample liquid injected from the introducing portion, and plural reactor portions which hold the sample liquid therein to be mixed with the reagent, thereby to react. A movable driver portion is provided on which the carrier is mounted and a reagent charging device is provided for ejecting the reagents which are different for the respective plural reactor portions of the carrier, sequentially. Further, a detector is provided for detecting the components after mixing the reagents with the sample liquid.

Abstract: A method for measuring low levels of a substance in a sample includes the formation of a rotor from paramagnetic particles in a substantially uniform magnetic field. The rotor is rotated by rotating the substantially uniform magnetic field. A portion of the substance in a sample is bound to the paramagnetic particles, and a signal having a time-varying component is detected. The signal is then processed using a lock-in amplifier with a reference signal having a frequency twice that of the rotation of the magnetic field. This improves the signal-to-noise ratio of the time-varying component of the signal.

Abstract: The present invention provides an apparatus and method for storing a particle-containing liquid. The storage apparatus comprises a microfluidic convoluted flow channel having a plurality of article capture regions. The storage channel is preferably an isotropic spatially periodic channel. Sedimented particles can be resuspended following storage. This invention further provides a microfluidic analysis cartridge having a convoluted storage channel therein. The sample analysis can use optical, electrical, pressure sensitive, or flow sensitive detection. A plurality of analysis channels can be included in a single cartridge. The analysis channels can be joined to reagent inlets for diluents, indicators or lysing agents. A mixing channel can be positioned between the reagent inlet and the analysis region to allow mixing and reaction of the reagent. The cartridge can include additional valves and pumps for flow management.

Abstract: A process analytic system provides communication between a process analyzer and process sample handling system. The communication allows the process analyzer to modify at least one parameter of the sample handling system to facilitate quick and efficient setup, calibration, and maintenance of the process analytic system. The process analytic system includes a sample handling system that is coupled to a process analyzer to provide a process sample to the process analyzer, and to communicate with the process analyzer. The process analyzer can command the sample handling system to modify at least one sample handling parameter. The process analyzer can modify sample handling parameters based upon sample analysis, diagnostics of the sample handling system, or both.

Abstract: A work station for simultaneously performing multiple assays includes a base structure, a receptacle rack assembly received within a receptacle rack well formed in the base structure, a pipette tip rack assembly received within a pipette tip rack well formed in the base structure, a multiple conduit substance transfer device, and substance transfer device positioning structure. The receptacle rack assembly holds a plurality of receptacles in which a plurality of individual assays are performed, and the pipette tip rack assembly holds a plurality of contamination limiting pipette tips. The substance transfer device is capable of simultaneously dispensing substances into two or more receptacles or simultaneously removing substances from two or more receptacles. Alternatively, the substance transfer device is capable of simultaneously dispensing substances into two or more receptacles, and, at about the same time, simultaneously removing substances from two or more receptacles.

Abstract: The present invention relates to antioxidant analysis for solder plating solutions, by using a complexing solution comprising a molybdenum compound, such as MoO2Cl2, to form a highly colored antioxidant-molybdenum complex, which can be detected and analyzed by UV-Vis spectroscopic, as a basis for concentration determination for the antioxidant.

Abstract: The adsorption rate of proteins from solutions on surfaces in the region of interface layers is often so large that a depletion of the protein in the interface layer results. Due to this, the total reaction becomes transport-dependent, sensitively disrupting the determination of the rate constants. In known TIRF-analysis chambers or bio-sensor systems with a liquid interface layer of ˜10 ?m thickness and mass transport coefficients of 10?6-10?5 m/s it has up limitation. With the help of a TIRF-flow-through shear analyzer in which a certain volume unit of an immiscible fluid, for example an air bubble, is fed into the buffer flow, an ultra-thin liquid layer arises on the surface with a thickness of 100-200 nm, wherein interface surfaces below 10 nm thickness are technically possible.

Abstract: What is described in this case is a laboratory microchip having microspray means whose direction of spray can be altered. The microchip has a substrate 40 which has a channel structure provided on one side 41 thereof. On the other side (in the region of an edge of the substrate in the present case), there is a microspray tip 42. Substrate 40 is designed to be deformable particularly in a region 43, in which case the deformability may be achieved either by thinning the substrate material locally in this region 43 or by means of a linear perforation extending approximately perpendicularly to the plane of the paper. Alternatively, the deformability may be obtained by selecting a suitable material for the entire substrate. A microchip which has been bent in the manner indicated is shown in the bottom part of FIG. 3. The bending of the substrate which is shown has turned the direction of spray 44 of microspray tip 42 through 90°. The bending of the substrate may be permanent or reversible in this case.

Abstract: A single pass analyzer includes multiple infrared sensors, a catalytic converter, a scrubber and a thermal conductivity cell all coupled in series to provide a single pass (i.e., one sample) analyzer which allows for fast analysis, allows for the speciation of hydrogen samples, requires no purging between different sample types, utilizes a single carrier gas, and eliminates molecular sieves and Shutze converters. The resultant analyzer provides improved quicker results with less plumbing (i.e., gas conduits and valving) in a single instrument.

Abstract: A flow of liquids is carried out on a microscale utilizing surface effects to guide the liquid on flow paths to maintain laminar flow. No sidewall confining structure is required, minimizing resistance to flow and allowing laminar flow to be maintained at high flow rates. The guiding structure has flow guiding stripes formed on one or both of facing base and cover surfaces which are wettable by a selected liquid to direct the liquid from a source location to a destination location. The regions adjacent to the guiding stripes on the base and cover surfaces are non-wettable. The smooth interface between the gas and liquid along the flowing stream allows gas-liquid reactions to take place as a function of diffusion across the interface without mixing of the gas and liquid. Liquid-liquid flows may also be guided with such structures.

Abstract: A microchip comprises a flow pass in which a solution containing particles can flow, and a deflection mechanism for deflecting a portion of the particles as the particles flow through the flow pass.

Abstract: Non-planar microfluidic devices and methods for transferring fluids between vessels and microfluidic devices are provided. The devices may be contoured to physically contact non-planar vessels, such as pipes, tubes, vials, or syringes to establish fluid communication between a vessel and a microfluidic device. Devices according to the invention may be constructed from flexible, rigid, or combinations of flexible and rigid materials. In certain embodiments, microfluidic devices are composed of sandwiched stencils, and self-adhesive tapes may be used for one or more layers. A microfluidic device may be removably attached to a vessel with a non-permanent adhesive or adhesive layer. Continuously wrapped microfluidic devices fashioned from a single layer, in addition to rewindable microfluidic devices constructed from multiple layers, are provided. A multi-plunger syringe permits a microfluidic device or other reservoir coupled to the vessel to be filled on the draw stroke of the syringe plunger.

Abstract: An apparatus for synthesizing polymer chains includes a controller, a plurality of precision fit vials circularly arranged in multiple banks on a cartridge, a drain corresponding to each bank of vials, a chamber bowl, a plurality of valves for delivering reagents to selective vials, and a waste tube system for purging material from the vials. A purging operation can be selectively performed on one or more of the banks of vials. The multiple banks of valves provide an additional number of reagent choices while operating in a serial mode and faster reagent distribution while operating in a parallel mode. The plurality of vials are stored in the cartridge and are divided among individual banks wherein each bank of vials has a corresponding drain. There is at least one waste tube system for expelling the reagent solution from vials within a particular bank of vials when the waste tube system is coupled to the corresponding drain.

Abstract: An apparatus is provided for hematology testing, which has a sensing unit defining a counting orifice for the flow of a blood sample through the counting orifice to analyze the blood sample, and a pump unit having three syringes. A first syringe is coupled in fluid communication with the sensing unit on the inlet side of the counting orifice for injecting a stream of blood sample through the counting orifice. A second syringe is coupled in fluid communication with the sensing chamber on the inlet side of the counting orifice for simultaneously injecting a sheath of fluid surrounding the sample stream on the inlet side of the counting orifice. And a third syringe is coupled to the sensing chamber on the outlet side of the counting orifice for aspirating a sheath of fluid from the sensing chamber surrounding the sample stream on the outlet side of the counting orifice.

Abstract: A sampler for automatic elemental analysers, of the “drawer” type, has a loading device, a guide, a joining block for joining the loading device and the guide, an admission piston, a purge chamber for a sample to be analysed, a system for injecting a purge gas into the purge chamber, which in its turn has: an inner passage of the admission piston, the admission piston being movable between a drop position and an feeding position for the sample to be analysed; a passage of the joining block; a passage of the loading device aligned with the drop position for the sample to be analysed. A device to direct the flow in the purge chamber is disposed within the purge chamber in order to avoid the phenomenon of retro-diffusion of the ambient atmospheric gases in the purge chamber.

Abstract: The invention relates to a microfabricated device for use in measuring the physical properties of compounds, where the properties measured using such devices are those which involve partitioning of the compound between two phases, measuring partition coefficients, distribution coefficients, acid-base dissociation constants, solubility and vapour pressure. The device comprises a microfabricated conduit, in which two fluids flow creating at least two phases between which the compound may partition, and a detector for measuring the amount of compound in each or both fluids.

Abstract: A liquid outlet link assembly is provided for liquid delivery output rates below 10 &mgr;l per minute so as to smooth out the flow from a positive displacement pump which has an immediate step pumping rate which is relatively substantially larger than the delivery rate required through the liquid outlet means. Essentially, this liquid link assembly has a bubble of air or some other pressure activated expansion means which initially contracts on the step pump such as a syringe pump operation and then gradually expands over time, allowing a steady output rate through the link assembly.

Abstract: A system for the detection of contaminates of a fluid in a conduit. The conduit is part of a fluid distribution system. A chemical or biological sensor array is connected to the conduit. The sensor array produces an acoustic signal burst in the fluid upon detection of contaminates in the fluid. A supervisory control system connected to the fluid and operatively connected to the fluid distribution system signals the fluid distribution system upon detection of contaminates in the fluid.

Abstract: An analyzer and a structure for analysis with high performance are provided which can reduce contamination between the reagents when the valve components or a plurality of reagents are included.

Abstract: The present invention provides an apparatus and method of reducing noise associated with biomolecular measurement systems. Sensor detection system noise characteristics in the presence of other sensor detection systems are determined and advantageously used to determine an arrangement of the individual sensor cells. The sensor cells are arranged on a substrate such that the system noise is determinable and can thus be filtered from the measurement signal.

Abstract: An automatic analyzer in which, without causing an increase in size and complication of the analyzer, the efficiency of washing cuvettes can be increased and the amount of detergent used can be more effectively saved in comparison with known analyzers. In an automatic analyzer in which a sample and a reagent are dispensed into each of a plurality of cuvettes, a resulting reaction solution is mixed under stirring, and reaction states of the mixed reaction solution are measured successively, the automatic analyzer includes a unit for stirring a detergent in the cuvette when the interior of the cuvette is washed with the detergent after measurement of a reaction occurred in the reaction solution. The automatic analyzer includes a control device controlling steps of reaction measurement and washing carried out in the automatic analyzer and incorporating a sequence of stirring in the washing step. Ultrasonic washing having a high washing effect is used as the unit for stirring a detergent in the cuvette.

Abstract: A microfluidic device for forming and/or dispensing minute volume segments of a material is described. In accordance with one aspect of the present invention, a microfluidic device and method is provided for spatially confining the material in a focusing element. The device is also capable of segmenting the confined material into minute volume segments, and dispensing a volume segment to a waste or collection channel. The device further includes means for driving the respective streams of sample and focusing fluids through respective channels into a chamber, such that the focusing fluid streams spatially confine the sample material. The device may also include additional means for driving a minute volume segment of the spatially confined sample material into a collection channel in fluid communication with the waste reservoir.