Abstract: Flow rates in a microfluidic device are modulated after performing serial dilutions by flow reduction channels that draw fluid from the main channel, thus reducing the flow rate. The reduction in flow rate and/or use of smaller dimension channels allow reduced reagent consumption. In addition, multiple flow reduction channels are used for multiple concentration measurements and for performing multiple assays simultaneously on a single sample. Also included are microfluidic devices and integrated systems for performing assays using serial dilutions, single pressure sources, multiple concentration measurements, and reduced reagent consumption. Devices comprising flow reduction channels are also used to suppress pressure perturbations from spontaneous injection.

Abstract: Methods and systems for performing single molecule amplification for detection, quantification and statistical analysis of rare nucleic acids are provided.

Abstract: Methods devices and systems that employ non-mechanical valve modules for controlling directing fluid and other material movement through integrated microscale channel network. These non-mechanical valve modules apply forces that counter the driving forces existing through a given channel segment, via fluidly connected channel segments, so as to selectively arrest flow of material within the given channel segment.

Abstract: Methods devices and systems that employ non-mechanical valve modules for controllably directing fluid and other material movement through integrated microscale channel networks. These non-mechanical valve modules apply forces that counter the driving forces existing through a given channel segment, via fluidly connected channel segments, so as to selectively arrest flow of material within the given channel segment.

Abstract: Microfluidic devices, systems, and methods measure viscosity, flow times, and/or other flow characteristics within the channels, and the measured flow characteristics can be used to generate a desired flow. Multi-reservoir pressure modulator and pressure controller systems, electrokinetic systems and/or other fluid transport mechanisms can generate the flow, controllably mix fluids, and the like.

Abstract: Arrays of flowable or fixed particle sets are used in microfluidic systems for performing assays and modifying hydrodynamic flow. Also provided are assays utilizing flowable or fixed particle sets within a microfluidic system, as well as kits, apparatus and integrated systems comprising arrays and array members.

Abstract: Electrokinetic devices having a computer for correcting for electrokinetic effects are provided. Methods of correcting for electrokinetic effects by establishing the velocity of reactants and products in a reaction in electrokinetic microfluidic devices are also provided. These microfluidic devices can have substrates with channels, depressions, and/or wells for moving, mixing and monitoring precise amounts of analyte fluids.

Abstract: Methods devices and systems that employ non-mechanical valve modules for controllably directing fluid and other material movement through integrated microscale channel networks. These non-mechanical valve modules apply forces that counter the driving forces existing through a given channel segment, via fluidly connected channel segments, so as to selectively arrest flow of material within the given channel segment.

Abstract: Microfluidic devices, systems, and methods measure viscosity, flow times, and/or other flow characteristics within the channels, and the measured flow characteristics can be used to generate a desired flow. Multi-reservoir pressure modulator and pressure controller systems, electrokinetic systems and/or other fluid transport mechanisms can generate the flow, controllably mix fluids, and the like.

Abstract: Methods and devices for inducing high bulk hydrodynamic resistance and/or for inducing low electrical resistance in microscale systems including bulk viscosity enhancers, surfactants, and electrolytes. High bulk hydrodynamic resistance is optionally utilized to regulate the effects of spontaneous injection and/or dispersion. Induced high hydrodynamic resistance in conjunction with induced low electrical resistance are optionally utilized to provide and regulate electrical fields within microfluidic devices. Integrated systems incorporating the methods of the invention are also provided.

Abstract: Nucleotides and nucleotide analogs are used in various sequencing by incorporation/sequencing by synthesis methods. Nucleotide analogs comprising 3′-blocking groups are used to provide reversible chain-termination for sequencing by synthesis. Typical blocking groups include phosphate groups and carbamate groups. Fluorescent nucleotides are used to perform sequencing by synthesis with detection by incorporation of the fluorescently labeled nucleotide, optionally followed by photobleaching and intercalating dyes are used to detect addition of a non-labeled nucleotide in sequencing by synthesis with detection by intercalation. Microfluidic devices, including particle arrays, are used in the sequencing methods.

Abstract: Methods for monitoring time dependent reactions that comprise providing a flow channel, typically microscale in dimension, flowing at least two reagents into the flow channel and varying the flow rate of the mixture through the flow channel. By increasing and/or decreasing the flow rate of the reagent mixture from the point of mixing to the point of detection, one alters the amount of reaction time, allowing monitoring reaction kinetics over time.

Abstract: Arrays of flowable or fixed particle sets are used in microfluidic systems for performing assays and modifying hydrodynamic flow. Also provided are assays utilizing flowable or fixed particle sets within a microfluidic system, as well as kits, apparatus and integrated systems comprising arrays and array members.

Abstract: Microfluidic devices, systems, and methods measure viscosity, flow times, and/or other flow characteristics within the channels, and the measured flow characteristics can be used to generate a desired flow. Multi-reservoir pressure modulator and pressure controller systems, electrokinetic systems and/or other fluid transport mechanisms can generate the flow, controllably mix fluids, and the like.

Abstract: Electrokinetic devices having a computer for correcting for electrokinetic effects are provided. Methods of correcting for electrokinetic effects by establishing the velocity of reactants and products in a reaction in electrokinetic microfluidic devices are also provided. These microfluidic devices can have substrates with channels, depressions, and/or wells for moving, mixing and monitoring precise amounts of analyte fluids.

Abstract: Electrokinetic devices having a computer for correcting for electrokinetic effects are provided. Methods of correcting for electrokinetic effects by establishing the velocity of reactants and products in a reaction in electrokinetic microfluidic devices are also provided. These microfluidic devices can have substrates with channels, depressions, and/or wells for moving, mixing and monitoring precise amounts of analyte fluids.

Abstract: Methods, systems, kits, and apparatus for calculating kinetic and concentration information in microscale systems are provided. Dwell times for access by a microfluidic system are varied and the resulting modulation of signal profile information used to provide a first order estimation of an activity of a potential activity modulator accessed by the system.

Abstract: Nucleotides and nucleotide analogs are used in various sequencing by incorporation/sequencing by synthesis methods. Nucleotide analogs comprising 3′-blocking groups are used to provide reversible chain-termination for sequencing by synthesis. Typical blocking groups include phosphate groups and carbamate groups. Fluorescent nucleotides are used to perform sequencing by synthesis with detection by incorporation of the fluorescently labeled nucleotide, optionally followed by photobleaching and intercalating dyes are used to detect addition of a non-labeled nucleotide in sequencing by synthesis with detection by intercalation. Microfluidic devices, including particle arrays, are used in the sequencing methods.

Abstract: Microfluidic devices for performing integrated reaction and separation operations. The devices comprise a planar substrate having a first surface with an integrated channel network disposed therein. The reaction region in the integrated microscale channel network has a mixture of at least first and second reactants located therein, wherein the mixture interacts to produce one or more products. The reaction region is configured to maintain contact between the first and second reactants contained within it. The device also includes a separation region in the integrated channel network, where the separation region is configured to separate the first reactant from the product, when the first reactant and product are flowing through the separation region.

Abstract: Methods and systems for particle focusing to increase assay throughput and sensitivity in microscale systems are provided. The invention includes methods for providing substantially uniform flow velocity to flowing particles in microfluidic devices. Methods of sorting members of particle populations, such as cells and various subcellular components are also provided. Integrated systems in which particles are focused and/or sorted are additionally included.