Abstract: A chromatograph is provided for identifying components of a mixture. Components are identified by different rates of adsorption and/or desorption with a material phase. In one embodiment, an electrical lead is connected to the material phase for supplying an electrical charge to the material phase. The electrical charge alters the rate of adsorption/desorption of the components with the material phase. In another embodiment, the material phase is disposed between two conductors with electrical leads connected to each of the conductors. A charge differential between the two conductors alters the rate of adsorption and/or desorption of components with the material phase.

Abstract: A method of driving a pump is used in a pressure-applying apparatus, the apparatus including a flow passage, a pump configured to impart pressure into the flow passage, an opening and closing valve configured to open and close the flow passage, a pressure detector configured to detect pressure in the flow passage, and an atmospheric air open valve configured to open an interior of the flow passage to atmospheric air. The method includes driving the pump after closing the opening and closing valve and opening the atmospheric air open valve, and evaluating a state of the pump, based on one of: the pressure detected by the pressure detector at a time at which a predetermined time period has elapsed after closing the atmospheric air open valve, and a time from closing of the atmospheric air open valve until detection of a predetermined pressure by the pressure detector.

Abstract: An optical system for particle detection.

Abstract: The present disclosure relates to fluidic systems and devices for processing, extracting, or purifying one or more analytes. These systems and devices can be used for processing samples and extracting nucleic acids, for example by isotachophoresis. In particular, the systems and related methods can allow for extraction of nucleic acids, including non-crosslinked nucleic acids, from samples such as tissue or cells. The systems and devices can also be used for multiplex parallel sample processing.

Abstract: A chromatographic column assembly is described, comprising a channel and a flow inducer. The channel comprises an inlet for receiving a sample liquid and an outlet, and is adapted for separating the sample liquid into components when the sample liquid flows through the channel in an axial direction from the inlet to the outlet. The flow inducer is adapted for controllably inducing, when the sample fluid is flowing through the channel, a motion of the sample liquid in the channel in a plane substantially orthogonal to the axial direction.

Abstract: The present disclosure relates to fluidic systems and devices for processing, extracting, or purifying one or more analytes. These systems and devices can be used for processing samples and extracting nucleic acids, for example by isotachophoresis. In particular, the systems and related methods can allow for extraction of nucleic acids, including non-crosslinked nucleic acids, from samples such as tissue or cells. The systems and devices can also be used for multiplex parallel sample processing.

Abstract: The present invention provides devices and methods for identification and/or quantitation of particles through detection of fluorescence labeled particles in an apparatus for differential charged particle mobility analysis and fluorescence detection.

Abstract: A method and apparatus for determining a radius of particles suspended in a medium includes superposing first and second Doppler-shifted optical waves having a variable frequency shift between them in the medium such that there is a gain in energy of the first optical wave with respect to the second optical wave, varying the frequency shift and measuring the gain while varying the frequency shift to determine the value of the frequency shift at which there is a peak in the gain, and determining the radius of the particles based on the value of the frequency shift at which there is a peak in the gain.

Abstract: A particle detector includes a housing, a light source, and a photo-responsive material. The housing includes a sample inlet and a sample outlet, and encloses a detection cavity. The light source directs irradiating light to particles of a sample fluid flowing in the detection cavity. The photo-responsive material faces the detection cavity, and receives measurement light propagating from the particles in a plurality of measurement light paths angled relative to a longitudinal axis. The particle detector may be utilized to measure scattered light and/or light emitted due to autofluorescence. Fluids sampled may include aerosols, bio-aerosols, and liquids.

Abstract: A method of manufacturing at least one customized MIP unit including: (a) providing at least one MIP unit having a surface including at least one target binding site configured to resemble a target molecule and surface-bound chargeable groups; (b) contacting the MIP unit(s) from the step (a) with at least one template molecule in a first solvent allowing the template molecule(s) to bind to the MIP unit(s); (c) passivating the surface-bound chargeable groups on the MIP unit(s) by adding a passivating agent; and (d) removing the template molecule(s) by washing in a second solvent, wherein the passivating agent binds to the surface of the unit(s) through bonds which remain stable upon washing in the second solvent.

Abstract: A high-throughput optical suspension characterization instrument is disclosed, which can include hydraulically separate and at least partially transparent sample containers. A selection mechanism is operative to selectively direct light from a light source (12) through different ones of the sample containers along an optical axis, and an off-axis scattering detector (38,24) is responsive to scattered light from the light source after it has interacted with a sample. Phase analysis light scattering is used to determine the electrophoretic mobility and zeta potential of samples. A second instrument is disclosed, wherein all sample containers are illuminated simultaneously. Transmitted light is collected by a camera. The electrophoretic mobility and hydrodynamic size of the samples may be determined.

Abstract: The present invention is configured to be provided with: a bottom-equipped tubular cell main body that forms an internal space S1 that extends in a longer direction, and has one end part that is opened; a pair of applying electrodes that are arranged so as to face to each other in the internal space; and a fixing spacer that intervenes between the pair of applying electrodes to thereby define a distance between the applying electrodes, and fixes the pair of applying electrodes, wherein in a state where the fixing spacer is inserted into the cell main body, in a lower part of the internal space of the cell main body, a zeta potential measuring space in which the pair of applying electrodes are exposed is formed.

Abstract: Embodiments of analysis systems, electrophoresis devices, and associated methods of analysis are described herein. In one embodiment, a method of analyzing a sample containing an electrolyte includes sequentially introducing a leading electrolyte, a sample electrolyte, and a trailing electrolyte into a extraction channel carried by a substrate. The extraction channel has a constriction in cross-sectional area. The method also includes applying an electrical field to separate components of the sample electrolyte into stacks and to concentrate the separated components by forcing the sample electrolyte to migrate through the constriction in the extraction channel. Thereafter, the applied electrical field is removed and the separated and concentrated components of the sample are detected in a detection channel carried by the substrate.

Abstract: Improved electrophoretic analysis is provided by interaction of anionic and cationic isotachophoresis (ITP) shock waves that propagate toward each other, and analysis of the resulting interaction zones. These shock wave interactions can provide qualitatively different capabilities from conventional ITP methods. Shock wave interaction can enable a single assay to identify analyte and quantify its concentration via isotachophoretic focusing followed by separation of the concentrated analytes via electrophoresis, without any mid-assay alteration of the externally imposed experimental conditions (i.e., no switching, valve operation, etc. during the measurement). As another example, shock wave interaction can enable a single assay to provide coupled ITP processes with different electrolyte concentrations (as in cascade-ITP) in a single simple system (again, without any mid-assay alteration of the externally imposed experimental conditions).

Abstract: The invention relates to mutant forms of lysenin. The invention also relates to analyte characterisation using lysenin.

Abstract: The present invention provides a system including: a peptide nucleic acid (PNA) molecule; a DNA molecule, an RNA molecule, or a combination thereof; and an Isotachophoresis (ITP) system. Furthermore, the invention provides a method for sequence-specifically separating and/or identifying a nucleic acid molecule of interest by utilizing the system of the invention to separate and possibly label and/or detect a nucleic acid molecule of interest.

Abstract: Isotachophoresis (ITP) is exploited to control various aspects of chemical reactions. In a first aspect, at least one of the reactants of a chemical reaction is confined to an ITP zone, but the resulting product of the chemical reaction is separated from this ITP zone by the ITP process. In a second aspect, one or more reactants of a chemical reaction are confined to an ITP zone, and one or more other reactants of the chemical reaction are not confined to this ITP zone. In a third aspect, ITP is employed to confine at least one reactant of a chemical reaction to an ITP zone, and at least one reactant of the chemical reaction is delivered to the ITP zone in two or more discrete doses. These aspects are especially relevant to performing polymerase chain reactions using chemical denaturants as opposed to thermal cycling.

Abstract: The invention relates to a method and apparatus for carrier-free deflection electrophoresis, in which a separating media and a sample to be examined flow through a separating chamber between a pair of electrodes in a series of reversing bulk fluid flow along the direction of the electrodes, thereby separating the sample into zones which are to be collected into fractions for analysis or further processing. Among other things, the apparatus and method enable high-resolution separation of particles that can be performed in miniaturized chambers in electrophoresis modes including isoelectric focusing, zone electrophoresis, and isotachophoresis.

Abstract: Methods are provided for forming a complex comprising an analyte (or an analyte analog) from a blood-derived sample and labeling substances, and separating the complex from excess labeling substances and coexisting substances from the blood-derived sample, in a rapid, simple, convenient, and highly precise isotachophoresis (ITP) process by adding 2-(N-morpholino)ethane sulfonate (MES) salt and/or glutamate salt to the ITP sample. Methods are also provided for measuring the analyte in blood-derived samples with high precision and high sensitivity, based on the amount of the complex separated or the amount of uncomplexed labeling substance-containing molecules.

Abstract: An electrode for use in instruments capable of measuring the electrophoretic mobility of particles in solution is disclosed. The electrode is comprised of an inexpensive support member, generally made of titanium, onto a flat surface of which has been connected, generally by microwelding, a flat electrically conductive but chemically inert foil member, preferably platinum. A uniform texture can be generated on the exposed surfaces of the electrode by various means including tumbling the electrode with an abrasive. An oxide layer can be generated on the support member by soaking the composite electrode in an appropriate medium, protecting the exposed surface of the support member from fluid contact with the sample solution, while the foil member, unaffected by the oxidation process, is able to contact the sample solution.

Abstract: The present invention provides methods, devices, and kits for separating and selecting top sperm from a sperm sample of a subject. In one aspect, for example, such a method can include removing a portion of negatively charged protein from sperm in the sperm sample, immobilizing the sperm, electrophoretically separating the sperm, and selecting mature sperm based on electromotility properties.

Abstract: An apparatus for measuring information indicative of electromobility in a sample includes a light source for generating coherent light, a modulator that modulates the optical path length, particularly a reciprocatable modulator arranged for modulating a first part of the generated light, a sample cell for accommodating the measured sample for applying an electric field to the sample and for receiving a second part of the generated light for interaction with the sample in the electric field, a modulator monitor for monitoring the modulator by detecting interference between a first part of the light coming from the modulator and an unmodulated third part of the generated light, and a light detector arranged separately from the modulator monitor for detecting interference between a second part of light coming from the modulator and light received from the sample cell. The detected signal includes the information indicative of electromobility in the sample.

Abstract: A novel method for visualizing electrokinetic process zones (e.g., for isotachophoresis (ITP)) is provided. We introduce negligibly small concentrations of a fluorophore that is not focused by isotachophoresis. This non-focusing tracer (NFT) migrates through multiple isotachophoresis zones. As it enters each zone, the NFT concentration adapts to the local electric field in each zone. ITP zones can then be visualized with a point detector or camera. The method can be used to detect, identify, and quantify unknown analyte zones, and can visualize complex and even transient electrophoresis processes. This visualization technique is particularly suited to microfluidic and lab-on-a-chip applications, as typical fluorescence microscopes and CCD cameras can provide high-resolution spatiotemporal data.

Abstract: A molecule trapping method includes forming a fluid bridge between a first reservoir and a second reservoir, translocating a molecule from the first reservoir to the second reservoir through the fluid bridge, detecting when a segment of the molecule is in the fluid bridge, breaking the fluid bridge and forming an a gap between the first and the second reservoirs, thereby trapping a segment of the molecule in the gap and making measurements on the segment of the molecule.

Abstract: An electrophoretic mobility measurement cell includes a container having a rectangular parallelepiped internal space for introducing a sample solution, two electrodes for applying an electric field to the internal space, tubular sample injection and extraction portions in communication with the internal space, first and second caps for covering the sample injection and extraction portions and sealing the internal space, the first cap has a first side surface contacting an inner side surface of the tubular sample injection portion, the inner side surface formed so that the cross-sectional area of the tube increases with distance from the internal space, and the area of the cross section of the first side surface decreases in the direction of insertion of the first cap. The cell and electrode portions are formed integrally, the electrode portions are made disposable together with the cell, and bubbles are unlikely to remain during injection of the sample solution.

Abstract: Techniques for enhanced isotachophoresis assays using additives with spatial gradients include forming a concentration gradient of an additive along a channel from an input port to an output port. The channel is used for isotachophoresis with ions of a leading electrolyte having a first mobility greater than a mobility of an analyte, and ions of a trailing electrolyte having a second mobility less than the mobility of the analyte. The additive is different from both the leading electrolyte and the trailing electrolyte; and the additive has a third mobility that assures the analyte will encounter the additive. The method further comprises introducing a mixture of the trailing electrolyte and a sample including the analyte. The method further comprises applying an electric field to the channel; and, measuring the analyte.

Abstract: Exemplary embodiments provide systems and methods for concentrating, focusing and/or separating proteins using nanofluidic channels and/or their arrays. In embodiments, low-abundance proteins can be focused and separated with high resolution using separation techniques including isoelectric focusing (IEF), and/or dynamic field gradient focusing (DFGF) in combination with nanofluidic channels and/or multi-gate nanofluidic field-effect-transistors (FETs).

Abstract: The present invention is an apparatus and method for detecting the motion characteristics of particles in a flow channel. The apparatus includes first and second electrode groups, each having a pair of electrodes, which are arranged to be spaced apart from each other in a flow channel. The pair of electrodes function as both a drive electrode and a sensing electrode for directly applying voltage and measuring impedance between the electrodes. An operation control unit measures variation in electrical pulses generated in the first and second electrode groups, thus detecting motion characteristics of the particles. The present invention is advantageous in that it does not require complicated optical measuring instruments or analyzing instruments, and in that it can be used to easily detect the motion characteristics of particles in a flow channel merely by analyzing variation in electrical pulses without requiring preliminary information.

Abstract: An isotachophoresis method for preconcentrating and isolating a plurality n of charged analytes (Ai, with i=1 to n) contained in a sample is disclosed, wherein each one of the analytes Ai has an effective electrophoretic mobility ?Ai obeying the fully ordered relationship ?A1>?A2>etc.>?An, comprising the step of preparing a mixture of said sample and a number n?1 of spacer compounds (Sk, with k=1 to n?1) wherein each one of said spacer compounds (Sk) has an effective electrophoretic mobility ?Sk obeying the fully ordered relationship ?Ak>?Sk>?Ak+1. An axial electric field is applied along the longitudinal axis of a separation channel, thereby causing a preconcentration and separation of the analytes and spacers forming respective focused spacer zones and focused analyte zones that flow along the longitudinal axis.

Abstract: Methods are provided for forming a complex comprising an analyte (or an analyte analogue) from a blood-derived sample and labeling substances, and separating the complex from excess labeling substances and coexisting substances from the blood-derived sample, in a rapid, simple, convenient, and highly precise isotachophoresis (ITP) process by adding 2-(N-morpholino)ethane sulfonate (MES) salt and/or glutamate salt to the ITP sample. Methods are also provided for measuring the analyte in blood-derived samples with high precision and high sensitivity, based on the amount of the complex separated or the amount of uncomplexed labeling substance-containing molecules.

Abstract: Indirect detection and/or identification of analytes by ITP can be enhanced by adding a mixture of labeled carrier ampholytes (CAs) to the sample to provide a continuous range of mobility markers. Each analyte can be detected and quantified by corresponding gaps in the CA signal. This approach does not require a priori choice of fluorophores and can be readily applied (without extensive and specific design) to a wide range of analytes. Analyte identification can be expedited by computing a normalized signal integral (NSI) from the CA signals. Empirical calibrations can relate the NSI to effective mobility. Effective mobility results under two or more different pH conditions can be used to determine analyte pKa and fully ionized mobility, which are analyte properties that can facilitate analyte identification.

Abstract: Methods and devices for sequencing nucleic acids are disclosed herein. Devices are also provided herein for measuring DNA with nano-pores sized to allow DNA to pass through the nano-pore. The capacitance can be measured for the DNA molecule passing through the nano-pore. The capacitance measurements can be correlated to determine the sequence of base pairs passing through the nano-pore to sequence the DNA.

Abstract: Isotachophoresis (ITP) can be employed to simultaneously focus the target and ligand of an assay into the same ITP focus zone. The target and ligand can bind to each other in the ITP focus zone, and then the resulting bound complex can be detected (e.g., by fluorescence). The sensitivity of this approach can be greatly increased by the enhanced concentration of both target and ligand that ITP provides in the focus zone. Since ITP can be performed quickly, the resulting assay is both rapid and sensitive. Markers of bacterial urinary tract infections have been experimentally detected at clinically relevant concentrations with this approach. MicroRNA sequences have also been profiled with this approach, which is clinically relevant because MicroRNA is expected to provide useful markers for disease. In one experiment, miR-122 in human kidney and liver was detected and quantified.

Abstract: The invention provides apparatus for separation of particles and methods for using the apparatus. In an embodiment, the apparatus includes three arms extending radially from a central reservoir, each arm being associated with a separation electrode. At least one on the arms includes a separation medium. Using a sequence of driving and mobility-changing voltages, target particles can be separated from closely related particles within a sample. For example, single point mutations can be resolved from a sample containing predominantly wild type nucleic acids.

Abstract: A method of modifying the concentration of reactants and carrying out a chemical reaction on a microfluidic device in which first and second reactants are delivered into a reaction channel combined, the second reactant different from the first reactant and capable of reacting with the first reactant. The first reactant is subjected to a stacking process, thereby producing a first stacked reactant. The second reactant is subjected to the stacking process, thereby producing a second stacked reactant. The first stacked reactant is exposed to the second stacked reactant so that the first stacked reactant and the second stacked reactant undergo a chemical reaction.

Abstract: A device for producing at least one of fluid flows and particles flows includes a substrate having a substrate surface. The substrate surface includes a matrix including a plurality of regions having at least one of a different magnitude of a surface charge, a different sign of the surface charge, and a different height above the substrate. A fluid including at least partially electrically charged particles is disposed at the substrate surface. A first control element is configured to supply a plurality of electrical voltages to a plurality of electrode pairs. The electric field exerts a first force on a component of the fluid within an electrical double layer. The component is disposed adjacent to the substrate surface. The electric field exerts a second force within the double layer and outside the double layer, the second force is exerted on the at least partially electrically charged particles.

Abstract: Provided are a device for varying wetting properties and a device for separating particles using the same. The magnitude and switching period of a voltage applied to a droplet are changed to separate particles contained in the droplet based on mass or size. The device for varying wetting properties includes an electrode layer that is electrically conductive with one of different electrical polarities, an insulating layer disposed at one side of the electrode layer, and a droplet that is in contact with the other polarity and contains different particles desired to be separated. Wetting properties of the droplet are varied according to application of a voltage.

Abstract: Analysis of samples is facilitated. According to an example embodiment, an electrophoresis approach involves electrophoretically stacking and/or separating a sample or samples. An electrolyte and a mixture of one or more samples with another electrolyte are added to a microchannel or capillary. An electric field is applied to stack (and, in some applications, further separate) the one or more samples. Generally, the electric field and electrolyte are used to facilitate isotachophoretic (ITP) stacking. In some embodiments, a further electric field is applied and used with the electrolyte to facilitate subsequent capillary electrophoresis (CE).

Abstract: Isotachophoresis (ITP) is exploited to control various aspects of chemical reactions. In a first aspect, at least one of the reactants of a chemical reaction is confined to an ITP zone, but the resulting product of the chemical reaction is separated from this ITP zone by the ITP process. In a second aspect, one or more reactants of a chemical reaction are confined to an ITP zone, and one or more other reactants of the chemical reaction are not confined to this ITP zone. In a third aspect, ITP is employed to confine at least one reactant of a chemical reaction to an ITP zone, and at least one reactant of the chemical reaction is delivered to the ITP zone in two or more discrete doses. These aspects are especially relevant to performing polymerase chain reactions using chemical denaturants as opposed to thermal cycling.

Abstract: Improved resolution and detection of nanoparticles are achieved when a nanopore connecting liquid compartments in a device running on the Coulter principle is provided with fluid lipid walls. The fluid lipid walls are made of a lipid bilayer, and preferably include lipid anchored mobile ligands as part of the lipid bilayer. By varying the nature and concentration of the mobile ligand in the lipid bilayer, multifunctional coatings of lipids are provided.

Abstract: An isotachophoresis system for separating a sample containing particles into discrete packets including a flow channel, the flow channel having a large diameter section and a small diameter section; a negative electrode operably connected to the flow channel; a positive electrode operably connected to the flow channel; a leading carrier fluid in the flow channel; a trailing carrier fluid in the flow channel; and a control for separating the particles in the sample into discrete packets using the leading carrier fluid, the trailing carrier fluid, the large diameter section, and the small diameter section.

Abstract: A high-throughput optical suspension characterization instrument is disclosed, which can include hydraulically separate and at least partially transparent sample containers. A selection mechanism is operative to selectively direct light from a light source (12) through different ones of the sample containers along an optical axis, and an off-axis scattering detector (38,24) is responsive to scattered light from the light source after it has interacted with a sample. Phase analysis light scattering is used to determine the electrophoretic mobility and zeta potential of samples. A second instrument is disclosed, wherein all sample containers are illuminated simultaneously. Transmitted light is collected by a camera. The electrophoretic mobility and hydrodynamic size of the samples may be determined.

Abstract: The present invention is configured to be provided with: a bottom-equipped tubular cell main body that forms an internal space S1 that extends in a longer direction, and has one end part that is opened; a pair of applying electrodes that are arranged so as to face to each other in the internal space; and a fixing spacer that intervenes between the pair of applying electrodes to thereby define a distance between the applying electrodes, and fixes the pair of applying electrodes, wherein in a state where the fixing spacer is inserted into the cell main body, in a lower part of the internal space of the cell main body, a zeta potential measuring space in which the pair of applying electrodes are exposed is formed.

Abstract: Provided herein is a surface acoustic wave (“SAW”) sensor device including an isolation component of a target biomolecule. A sample containing the target biomolecule is separated by its size using electrophoresis, and sequentially reacts with a SAW sensor. In other words, the device is capable of detecting the target biomolecule by separating biomolecules using electrophoresis, and applying the separated biomolecules to the SAW sensor.

Abstract: An isotachophoresis method for preconcentrating and isolating a plurality n of charged analytes (Ai, with i=1 to n) contained in a sample is disclosed, wherein each one of the analytes Ai has an effective electrophoretic mobility ?Ai obeying the fully ordered relationship ?A1>?A2>etc.>?An, comprising the step of preparing a mixture of said sample and a number n?1 of spacer compounds (Sk, with k=1 to n?1) wherein each one of said spacer compounds (Sk) has an effective electrophoretic mobility ?Sk obeying the fully ordered relationship ?Ak>?Sk>?Ak+1. An axial electric field is applied along the longitudinal axis of a separation channel, thereby causing a preconcentration and separation of the analytes and spacers forming respective focused spacer zones and focused analyte zones that flow along the longitudinal axis.

Abstract: The present invention provides a portable circular electrophoretic device having uniform electric field over a small surface area. It also provides a multidirectional process of electrophoresis for separation of charged molecules thereby increasing the resolution of macromolecules.

Abstract: A method of carrying out a chemical reaction on a microfluidic device in which a first reactant at a first concentration is delivered into a reaction channel; within the reaction channel the concentration of the first reactant is changed from the first concentration to a second concentration; and while at the second concentration the first reactant is exposed to a second reactant.

Abstract: A method and apparatus is disclosed for measurement of the electrophoretic mobility of particles and molecules in solution. A sample of particles is placed in a cell containing two electrodes that apply an alternating electric field. A monochromatic light beam passes through the sample. Light scattered by the particles, along with the unscattered beam, is collected and collimated as it exits the cell. This beam is combined in free space with a phase modulated reference beam. The interference forms a frequency modulated speckle pattern, which is detected by a photodetector array. Each array element collects a narrow range of well-defined scattering angles. The signal from each is demodulated to extract the optical phase information providing a first-principle measurement of the electrophoretic mobility of the scattering particles. Each detector element provides a simultaneous independent measurement. This inherent parallelism drastically increases the amount of information available in a given time.

Abstract: The present invention relates to the qualitative and/or quantitative determination of a proteinaceous molecule in a plurality of samples by combining a particular labeling and fractionation strategy. In particular, each sample is provided with a dye chosen from a set of dyes, wherein each dye within the set of dyes emits luminescent light at a wavelength that is sufficiently different from the emitted luminescent light of the remaining dyes in the set of dyes to provide a different light signal when excited. Subsequent to labelling the proteinaceous molecule with the fluorescent dye, the samples are combined and fractionated by means of electrophoresis, the labeled proteinaceous molecule having a relative electrophoretic mobility that differs from the electrophoretic mobility of the proteinaceous molecule labeled with another dye within the set of dyes. After capturing separate images of the labeled proteinaceous molecule at different wavelengths, the images are aligned by means of image processing.

Abstract: The present invention relates to droplet-based particle sorting. According to one embodiment, a droplet microactuator is provided and includes: (a) a suspension of particles; and (b) electrodes arranged for conducting droplet operations using droplets comprising particles. A method of transporting a particle is also provided, wherein the method includes providing a droplet comprising the particle and transporting the droplet on a droplet microactuator.