Abstract: Methods and systems for controlling fluid flow through a cartridge for use in an assay of a fluid sample for detection of a target analyte. In one aspect, the cartridge includes a microfluidic device having a network of microfluidic channels, one or more reservoirs and one or more actuatable valves for controlling fluid flow from the reservoirs through the microfluidic channels. In some embodiments, the valve includes a deformable membrane movable between a closed configuration in which the membrane seals against the microfluidic device inhibiting fluid flow and an open configuration moved away from the microfluidic device to allow fluid flow through the microfluidic channels. Other valve embodiments utilize frangible membranes or user-removable membrane.

Abstract: A micromachined tube (microtube) suitable for microfluidic devices. The microtube is formed by isotropically etching a surface of a first substrate to define therein a channel having an arcuate cross-sectional profile, and forming a substrate structure by bonding the first substrate to a second substrate so that the second substrate overlies and encloses the channel to define a passage having a cross-sectional profile of which at least half is arcuate. The substrate structure is thinned to define the microtube and walls thereof that surround the passage.

Abstract: A microfluidic device comprises pumps, valves, and fluid oscillation dampers. In a device employed for sorting, an entity is flowed by the pump along a flow channel through a detection region to a junction. Based upon an identity of the entity determined in the detection region, a waste or collection valve located on opposite branches of the flow channel at the junction are actuated, thereby routing the entity to either a waste pool or a collection pool. A damper structure may be located between the pump and the junction. The damper reduces the amplitude of oscillation pressure in the flow channel due to operation of the pump, thereby lessening oscillation in velocity of the entity during sorting process. The microfluidic device may be formed in a block of elastomer material, with thin membranes of the elastomer material deflectable into the flow channel to provide pump or valve functionality.

Abstract: Cassette (50) performs assays, e.g. multiplexed protein biomarker assays. Wide, bubble-free, slow flows are produced from liquids stored on cassette (50), flowing over wide array (20) of ligand receptors on a capture surface. Flows of Reynolds Number less than about 1, preferably 1×10?1 to 5×10?3, are heated in region (34) preceding and including bubble removal system (128). Analyte is introduced through compressed septum (32). External actuations of displacement pumps (30, 37) and valves (137 A, B, and C) produce flows in response to flow-front optical sensors (150, 152). Elastic sheet provides pump and valve diaphragms and resilient expansion of mixing volume (131). Break-away cover portions are pistons. Heating is by conduction through cassette from external contact heater. Planar cassette body, when tilted from horizontal, enables upward flow from pumped storage (134, 135) to reaction (133) to waste (139), with buoyancy bubble removal before reaction.

Abstract: A sample analysis apparatus configured to automatically press a start button upon installation of a sample tube is provided. The sample analysis apparatus includes: a body of the sample analysis apparatus; a door housing which may be provided in an opened state or a closed state, and configured to be coupled to the body of the sample analysis apparatus by a hinge; a tube accommodating unit included in the door housing and configured to accommodate the sample tube; a start button included in the body of the sample analysis apparatus and configured to start analysis of the sample; and an operating member positioned at a first position which is distant from the start button the sample tube is not installed in the tube accommodating unit, and a second position which is configured to operate the start button when a sample tube is installed and the door housing is closed.

Abstract: A self-contained, fully automated, biological assay-performing apparatus includes a housing; a dispensing platform including a controllably-movable reagent dispensing system, disposed in the housing; a reagent supply component disposed in the housing; a pneumatic manifold removably disposed in the housing in a space shared by the dispensing platform, removably coupled to a fluidic transport layer and a plurality of reservoirs, wherein the fluidic transport layer, the reservoirs, and a test sample to be introduced therein are disposed in the housing in the space separate from the dispensing platform; a pneumatic supply system removably coupled to the pneumatic manifold in the housing in a space separate from the dispensing platform; and a control system coupled to at least one of the dispensing platform and the pneumatic supply system, disposed in the housing.

Abstract: Embodiments described herein provide micro-fluidic systems and devices for use in performing various diagnostic and analytical tests. According to one embodiment, the micro-fluidic device includes a sample chamber for receiving a sample, and a reaction chamber for performing a chemical reaction. A bubble jet pump is structured on the device to control delivery of a fluid from the sample chamber to the reaction chamber. The pump is fluidically coupled to one or more chambers of the device using a fluidic channel such as a capillary. A valve may be coupled to one or more chambers to control flow into and out of those chambers. Also, a sensor may be positioned in one or more of the chambers, such as the reactant chamber, for sensing a property of the fluid within the chamber as well as the presence of a chemical within the chamber.

Abstract: The present invention relates to filler fluids for droplet operations. According to one embodiment of this aspect, a droplet microactuator is provided and includes: (a) a first substrate comprising electrodes configured for conducting droplet operations on a surface of the substrate; (b) a second substrate spaced from the surface of the substrate by a distance sufficient to define an interior volume between the first substrate and second substrate, wherein the distance is sufficient to contain a droplet disposed in the space on the first substrate; and (c) a droplet arranged in the interior volume and arranged with respect to the electrodes in a manner which permits droplet operations to be effected on the droplet using the electrodes.

Abstract: Sample liquid is collected in a chamber downstream of a separating device. Adjoining the chamber are a plurality of channels which guide the sample liquid to one or more investigating regions.

Abstract: A sample processing apparatus includes a sample carrier receiving region configured to receive a sample carrier. The sample carrier includes at least one sample channel carrying at least one sample, at least one agent chamber carrying at least one agent to be moved to the at least one sample channel to facilitate processing of the at least one sample, and the at least one agent chamber includes at least one chamber cover covering at least one opening of the at least one agent chamber, inhibiting flow of the at least one agent from the at least one agent chamber to the at least one sample channel. The sample processing apparatus further includes a chamber opener configured to facilitate opening the at least one chamber cover. The sample processing apparatus further includes a fluid mover that moves the agent out of the at least one agent chamber after the at least one chamber cover is opened and into the at least one sample channel.

Abstract: There is disclosed an analysis device for the analysis of a liquid sample, said device comprising a substrate, said substrate at least partly having projections substantially vertical to the surface of said substrate, and having a height (H1), diameter (D1) and center-to-center distance (x1, y1) such, that lateral capillary flow of said liquid sample is achieved, wherein that said substrate comprises at least one substrate zone comprising projections substantially vertical to the surface of said substrate, and having a height (H2), diameter (D2) and center-to-center distance (x2, y2), such, that lateral capillary flow of said liquid sample is achieved and wherein at least one substance is applied at least partly between the projections in said at least one substrate zone. Moreover there is provided a method for the analysis of a sample. The device and method provide for instance improved control of the dissolution of a substance.

Abstract: A dual inlet microchannel device and a method for using the device to perform a flow-through kinetic assay are described. A microplate having an array of the dual inlet microchannel devices and in particular their specially configured flow chambers is also described. Several embodiments of the dual inlet microchannel devices and specially configured flow chambers are also described.

Abstract: A device for transporting, trapping and escaping a single biomaterial using a magnetic structure, and a method of transporting, trapping and escaping of the single biomaterial using the same are provided, and a method is provided for controlling movement and direction of the single biomaterial including soft magnetic micro structure and magnetic structure in a linear, square storage, apartment type, radial soft magnetic micro structure. Accordingly, the device for transporting, trapping and escaping a single biomaterial and the method for transporting, trapping and escaping single biomaterial using the same can control movement on the lap-on-a-chip with increased precision and ease, by using magnetic force, and thus can be advantageously used in the field of magneto-resistive sensor, or categorization of single cells or biomolecules.

Abstract: An apparatus for passive sorting of microdroplets including a main flow channel, a flow stream of microdroplets in the main flow channel wherein the microdroplets have substantially the same diameter and wherein the flow stream of microdroplets includes first microdroplets having a first degree of stiffness and second microdroplets having a second degree of stiffness wherein the second degree of stiffness is different than the first degree of stiffness. A second flow channel is connected to the main flow channel for the second microdroplets having a second degree of stiffness. A separator separates the second microdroplets having a second degree of stiffness from the first microdroplets and directs the second microdroplets having a second degree of stiffness into the second flow channel.

Abstract: An improved apparatus and method for dispersion of a labeling conjugate in a diagnostic assay, the result being a one-step assay. By eliminating a conjugate pad as in conventional lateral diagnostic devices, and forming a frazil ice pellicle (FIP), rehydration and flow are improved resulting in better reproducibility, improved sensitivity, and reduced costs of individual assay devices. The formation of a frazil ice film formed on a super cooled surface of a sample receiving means simplifies assay assembly. Lyophilization of the FIP improves the release of a sample/analyte/label matrix into a macro channel as in a direct flow assay, while at the same time allowing reagents to mix and flow, thereby optimizing the assay performance. The reagents of the conjugate and the formation of the FIP stabilize the conjugate proteins and provide extended shelf life to the diagnostic assay device.

Abstract: A system for treating liquids, comprising: especially for analysis and/or synthesis of liquids, a fluidics unit having at least one functional unit; at least one liquid storage unit of the first type; at least one liquid storage unit of second type; a first liquid line; and a second liquid line, wherein a flow of liquid through the first liquid line directed from the fluidics unit to the liquid storage unit of first type is blocked, at least at times, by means of a first valve, and a flow of liquid through the second liquid line in the direction from the liquid storage unit of second type to the fluidics unit is blocked, at least at times, by means of a second valve.

Abstract: A microfluidic system having a microchannel for the capillary transport of a liquid, in particular a body fluid for analytical purposes. The microchannel is provided with a surface coating comprising at least one hydrophilic substance selected from the group consisting of polyacrylic acid, polyacrylate, dextran sulfate and chondroitin sulfate. The invention also concerns a coating method that is suitable for this.

Abstract: A microfluidic passive device and a method for determining clotting time are described, of a fluid medium such as blood, of low production cost which can therefore be disposable. When optimised to determine blood clotting time, it requires a minimal whole blood sample (<5 ?L) and it is particularly suited to INR or PT determination, which can be used autonomously by patient without venipuncture. Monitoring, and processing means to interpret the results are comprised in an external coagulometer device. A production method for the manufacture of the microfluidic device is also provided.

Abstract: The present invention provides a bilayer membrane produced using a microchannel capable of easily forming bilayer membranes such as planar lipid bilayer membranes in large quantities, and a production method thereof. A process for producing a bilayer membrane of the present invention comprises forming a state where two liquid phases or liquid and gaseous phases each containing amphipathic molecules are alternately arranged in a microchannel, discharging one of the two liquid phases or the gaseous phase of the liquid and gaseous phases through branch minichannels formed in the wall on one side or in the walls on both sides to contact the remaining liquid phases adjacent to each other, and thereby forming a side-by-side arrangement of bilayer membranes comprising the amphipathic molecules.

Abstract: A system for processing analytes in samples includes an instrument and a cartridge. The cartridge includes fluid inputs, input and output valve assemblies, processing devices, fluid reservoirs, and channels for carrying samples from the fluid inputs to the fluid reservoirs. The valve assemblies include valves adapted to form a sealed fluid chamber in response to force applied by a movable head assembly of the instrument. Each fluid reservoir is adapted to mate and align with an air displacement pump interface member. A valve assembly includes a recess wall surrounding a recess and a valve assembly wall surrounding both the recess and the recess wall. The recess wall and the valve assembly walls are adapted to mate with and seal against a flexible sheet covering the recess, the recess wall, and the valve assembly wall. The cartridge and instrument include complementary features for finely and coarsely aligning instrument assemblies with portions of the cartridge.

Abstract: Control of fluid flow in a fluidic network is provided by controlling phase transitions of a phase-change material between a liquid phase and a non-fluid phase. The phase-change material is disposed at ports of the fluidic network where the fluidic network is in communication with an ambient. This advantageously provides control of pressure-driven flow within the fluidic network without altering properties of fluids within the fluidic network.

Abstract: A liquid dispenser for a microfluidic assay system is described. The dispenser includes at least one transfer pin for transferring a microfluidic sample of liquid to a target receptacle. A pin tip at one end of the transfer pin is structured to cooperate with an opening in the target receptacle. The tip uses a high voltage potential to transfer the sample from the pin to the receptacle.

Abstract: The invention provides an apparatus and methodology to carry out biochemical testing on a centrifugal platform using flow splitting technique. In conventional biochemical testing, reagents need to be loaded individually into each reservoir. By using the flow splitting technique in this invention, one reagent only need to be loaded once, then, it can be evenly distributed into each reaction chambers in single or multiple layers format. The invention greatly reduces the required manpower when large numbers of assays are integrated on one platform. Because of the invention, many medical examinations can be performed efficiently, thus reduce the waste of manpower, time and cost.

Abstract: A microfabricated device or component thereof, such as microfluidics or nanofluidics device having a uniform non-wetting or non-absorbing polymeric coating or surface modification formed on a surface thereof by ionization or activation technology such as plasma processing, to produce a surface energy of less than 15 mNm?1. The treatment enhances the free-flowing properties of a liquid through the device during use.

Abstract: In a method of moving droplets, local heat is applied to a surface portion of a droplet for an amount of time sufficient to create a Marangoni flow in the droplet. Droplets are suspended in an emulsion in a carrier liquid on a substrate. A laser beam is used to move one of the droplets. the droplet consists of a first substance and a carrier liquid consists of a second substance that is not mixable with the first substance. The droplet is placed in the carrier liquid, and the mixture is emulsified. The emulsified mixture is placed on a substrate. Then the local heat is applied to the surface of the droplet. The first substance may include oil and the second substance may include water.

Abstract: Embodiments of microfluidic hubs and systems are described that may be used to connect fluidic modules. A space between surfaces may be set by fixtures described herein. In some examples a fixture may set substrate-to-substrate spacing based on a distance between registration surfaces on which the respective substrates rest. Fluidic interfaces are described, including examples where fluid conduits (e.g. capillaries) extend into the fixture to the space between surfaces. Droplets of fluid may be introduced to and/or removed from microfluidic hubs described herein, and fluid actuators may be used to move droplets within the space between surfaces. Continuous flow modules may be integrated with the hubs in some examples.

Abstract: Systems and methods for detecting the presence of biomolecules in a sample using biosensors that incorporate resonators which have functionalized surfaces for reacting with target biomolecules. In one embodiment, a device includes a piezoelectric resonator having a functionalized surface configured to react with target molecules, thereby changing the mass and/or charge of the resonator which consequently changes the frequency response of the resonator. The resonator's frequency response after exposure to a sample is compared to a reference, such as the frequency response before exposure to the sample, a stored baseline frequency response or a control resonator's frequency response.

Abstract: The present invention provides microfluidic devices and methods using the same in various types of thermal cycling reactions. Certain devices include a rotary microfluidic channel and a plurality of temperature regions at different locations along the rotary microfluidic channel at which temperature is regulated. Solution can be repeatedly passed through the temperature regions such that the solution is exposed to different temperatures. Other microfluidic devices include an array of reaction chambers formed by intersecting vertical and horizontal flow channels, with the ability to regulate temperature at the reaction chambers. The microfluidic devices can be used to conduct a number of different analyzes, including various primer extension reactions and nucleic acid amplification reactions.

Abstract: A blood coagulation analyzer includes a detector and a controller. The detector includes a light source for emitting light to a prepared measurement sample and a light-receiving section for receiving light transmitted through the measurement sample. The controller is configured to performs operations comprising acquiring, based on the light detected by the detector, ratio information reflecting a ratio between a first value reflecting the intensity of the light transmitted through the measurement sample of a clotting reaction starting stage and a second value reflecting the intensity of the light transmitted through the measurement sample of a clotting reacting ending stage, and acquiring, based on the ratio information, a fibrinogen concentration in the blood sample.

Abstract: Microfluidic devices are provided for trapping, isolating, and processing single cells. The microfluidic devices include a cell capture chamber having a cell funnel positioned within the cell capture chamber to direct a cell passing through the cell capture chamber towards one or more a cell traps positioned downstream of the funnel to receive a cell flowing. The devices may further include auxiliary chambers integrated with the cell capture chamber for subsequent processing and assaying of the contents of a captured cell. Methods for cell capture and preparation are also provided that include flowing cells through a chamber, funneling the cells towards a cell trap, capturing a predefined number of the cells within the trap, interrupting the flow of cells, flowing a wash solution through the chamber to remove contaminants from the chamber, and sealing the predefined number of cells in the chamber.

Abstract: A detection chip is provided. The detection chip includes a substrate, an active reagent, a hydrophilic droplet and a lipophilic substance. The substrate includes a first containing slot, wherein the first containing slot includes a first space and a second space adjacent to each other. The active reagent is disposed in the first space of the first containing slot. The hydrophilic droplet is disposed in the second space of the first containing slot. The lipophilic substance is disposed in the first containing slot, wherein the lipophilic substance is immiscible to the active reagent and the hydrophilic droplet, and separates the active reagent from the hydrophilic droplet.

Abstract: The present invention provides an apparatus and method for performing heat-exchanging reactions on an electro wetting-based micro fluidic device. The apparatus provides one or multiple thermal contacts to an electro wetting-based device, where each thermal contact controls the part of the electro wetting-based device it communicates with to a designed temperature. The electrowetting-based device can be used to create, merge and mix liquids in the format of droplets and transport them to different temperature zones on the micro fluidic device. The apparatus and methods of the invention can be used for heat-exchanging chemical processes such as polymerase chain reaction (PCR) and other DNA reactions, such as ligase chain reactions, for DNA amplification and synthesis, and for real-time PCR.

Abstract: A chemiluminescence-based detection system and method for counting blood cells by capturing and isolating target blood cells flowing through a microfluidic chip and detecting light emitted by the captured target blood cells.

Abstract: Novel and improved systems and methods for high speed arraying, hybridization, quantitative development and/or assaying are provided. Some embodiments provide a web based arraying format. Some other embodiments provide a sheet based arraying format. Some embodiments use a drop on drop assaying or hybridization mode. In some embodiments, a substantially inert substrate is utilized. In some other embodiments, an interactive substrate is utilized.

Abstract: The present invention provides methods, systems and apparatus in which one fluid passes through an orifice or orifices and mixes with another fluid as it flows through a microchannel.

Abstract: Microfluidic system, including methods and apparatus, for processing fluid, such as by droplet generation. In some embodiments, the system may include a well and a channel component attached to the well. The channel component may include (a) a body, (b) an input tube (a “fluid pickup”) projecting from a bottom surface of the body and having an open bottom end disposed in the input well, (c) a microchannel, and (d) a passage extending through the input tube and the body and connecting the well to the microchannel. The system may be configured to receive a sample-containing fluid in the well and retain the sample-containing fluid below a top end of the passage, until a pressure differential is created that drives at least a portion of the sample-containing fluid from the well via the passage and through the microchannel.

Abstract: An automatic chemical analyzer in which a reaction solution is stirred by air ejected from an air ejection hole placed above a reaction container. The reaction region can be washed and cleaned sufficiently without causing damage, such as exfoliation of a coating reagent. A reaction container disk 161 is provided with a pore 240 and a pressure detector 241 connected with the pore. Before and after the stirring operation, the ejection hole (nozzle) 170 ejecting air is moved and the output value of the pressure detector is compared with a previously measured normal value. With a discharge pipe 1101 and a suction pipe 1102 inserted to the opening of the reaction container 1140 to be close to both ends of the opening and the side wall of the container, the reaction region 1150 at the bottom of the container is washed by continuous discharge and suction of cleaning fluid.

Abstract: A hematology analyzer is provided. In certain embodiments, the hematology analyzer comprises: a) a flow cell; b) a light source for directing light to the flow cell; c) a plurality of detectors for detecting a plurality of optical characteristics of a blood cell passing through the flow cell; and d) a data analysis workstation programmed to: i. enumerate test blood cells passing through the flow cell; and ii. flag a blood sample as containing lysis-resistant red blood cells or fragile white blood cells.

Abstract: A microfluidic device is provided including at least one chamber accessible by microfluidic channels characterized in that the surface of the channels and the chambers are patterned and comprise hydrophilic and hydrophobic areas. The surface energy in correspondence of the areas, i.e., the capillary force, being such that a liquid can be guided along the hydrophilic path, enter the chamber from one side, wet part of one surface of the chamber as a thin layer without touching the opposite surface of the chamber, thus avoiding to fill the volume inside the chamber in correspondence of the hydrophilic pattern until a second liquid, either sequentially or in parallel, comes to wet part of the opposite surface of the chamber and eventually touches the first liquid layer, resulting in a sudden coalescence and efficient mixing between the liquids.

Abstract: A microfluidic element for analyzing a bodily fluid sample for an analyte contained therein is provided, the element having a substrate, a channel structure that is enclosed by the substrate, and a cover layer, and is rotatable around a rotational axis. The channel structure of the microfluidic element includes a feed channel having a feed opening, a ventilation channel having a ventilation opening, and at least two reagent chambers. The reagent chambers are connected to one another via two connection channels in such a manner that a fluid exchange is possible between the reagent chambers, one of the reagent chambers having an inlet opening, which has a fluid connection to the feed channel, so that a liquid sample can flow into the rotational-axis-distal reagent chamber. At least one of the reagent chambers contains a reagent, which reacts with the liquid sample.

Abstract: A microvalve for controlling fluid flows, and a sealing device for sealing cavities in a microfluidic system, particularly in a lab-on-a-chip system, and a method for the production thereof. A sealing surface of a valve body, or a sealing element, respectively, rests on a sealing surface of a substrate and is pressed against the sealing surface of the substrate in a fluid-tight manner by means of a clamping element. The clamping element and/or the valve body, or the sealing element, respectively, are at least partially elastic.

Abstract: A microchip having a fluid circuit therein for passing a liquid is provided, wherein the fluid circuit has a first reservoir and a second reservoir for storing at least a part of the liquid, a first path connecting the first reservoir and the second reservoir, and a second path connecting the first reservoir and the second reservoir at a position different from the first path, and the first reservoir, the second reservoir, the first path, and the second path constitute a circular path capable of circulating the liquid.

Abstract: Apparatuses and methods for manipulating droplets are disclosed. In one embodiment, an apparatus for manipulating droplets is provided, the apparatus including a substrate, multiple arrays of electrodes disposed on the substrate, wherein corresponding electrodes in each array are connected to a common electrical signal, and a dielectric layer disposed on the substrate first side surface and patterned to cover the electrodes.

Abstract: The present invention provides novel methods and devices that employ microfluidic technology to generate molecular melt curves. In particular, the devices and methods in accordance with the invention are useful in providing for the analysis of PCR amplification products.

Abstract: A pipetting device is described comprising more than one pipetting unit, wherein said pipetting units are independently movable in Y and Z direction and comprise at least one module arranged in a staggered manner compared to the adjacent pipetting unit.

Abstract: The present invention relates to a micro-volume liquid ejection system, including an air pressure module, a micro-ejection unit which is connected with the air pressure module by a conduit, and a control circuit which is connected with the air pressure module and the micro-ejection unit respectively. The air is used as the pressure medium, resulting in improved cleaning process and reduced sample waste. The present invention includes an electric control circuit to pick up sample, eject sample and clean the conduits automatically, and enables handling of a multiplicity of samples. The present invention can be used for transferring or dispensing micro volume liquid including biological liquid on a nL and ?L scale.

Abstract: A method for assessing a corrosion inhibitor in a coolant, comprises providing a test kit comprising a first chamber containing an acid buffer and a solvent immiscible therein and a second chamber containing an indicator, the second chamber being in fluid communication with the first chamber and being configured such that retraction of the second chamber draws fluid into the first chamber and advancement forces fluid into the second chamber; drawing a coolant sample into the first chamber; contacting the coolant sample with the acid buffer and solvent in the first chamber and extracting the corrosion inhibitor into the solvent; allowing the solvent and buffer to separate in the first chamber; forcing a portion of the separated solvent into the second chamber; contacting the separated solvent with the indicator in the second chamber, and obtaining a visual indication of the presence of corrosion inhibitor in the coolant sample.

Abstract: A parallel processing system for processing samples is described. In one embodiment, the parallel processing system includes an instrument interface parallel controller to control a tray motor driving system, a close-loop heater control and detection system, a magnetic particle transfer system, a reagent release system, a reagent pre-mix pumping system and a wash buffer pumping system.

Abstract: A microfluidic flow cell subassembly, which may be assembled into a flow cell having fluidic connections outside of the main substrate, is described for encapsulating a sample to allow for subsequent controlled delivery of reagents to the sample, such as multiplexed in situ biomarker staining and analysis. Methods for fabricating the subassembly and assembled flow cell are also provided. The method includes the steps of adhering a gasket layer to a substrate layer, wherein the gasket layer may contain enclosed features and adhering an adherent layer to the gasket layer. The subassembly may be sealed against a solid support to form a flow cell.

Abstract: Devices and methods are disclosed herein for separating a supernate from a suspension. The apparatus consists of a sample zone, a controllable gate, and an analysis zone. The sample zone holds the suspension. The analysis zone passively transports a supernate formed from the suspension by capillary transport. A controllable gate prevents the suspension in the sample zone from flowing into the analysis zone. The controllable gate can be triggered after the supernate has separated from the suspension to allow the supernate to flow into the analysis zone.