Abstract: System, including methods and apparatus, for forming droplets of an emulsion. The system may include a channel junction at which a stream of sample fluid is divided into droplets by a dividing flow of carrier fluid. The system also may include one or more features configured to position sample fluid for reduced contact between the sample fluid and one or more surface regions of the channel junction, which may improve the consistency of droplet formation. In exemplary embodiments, sample fluid may be positioned by a step member produced by an increase in channel depth, and/or by directing flow of carrier fluid to form a barrier layer between sample fluid and a wall region, such as a ceiling region or floor region, of a channel network.

Abstract: Sample holding system, including methods and apparatus, including a holder defining a well having a wicking promoter that encourages flow of a sample to the bottom of the well. Methods of making and using the holder are also disclosed.

Abstract: A microfluidic device is provided with appropriate integrated structures to conduct large volume PCR and end-point or real-time capillary electrophoresis detection. The microfluidic device includes a substrate having an amplification chamber of a volume of nucleic acid, wells disposed on the substrate, flow channels connecting the wells and the chamber in the substrate to allow for solution flow through the chamber, and one or more separation channels provided in the substrate and connected to the chamber for separating and detecting a fraction of the amplified nucleic acid. The chamber, the flow channels, and the one or more separation channels are configured such that the hydrodynamic flow resistance of the chambers and the flow channels combined is at least 10?3 times smaller than the hydrodynamic flow resistance in the one or more separation channels. The microfluidic device can achieve a very high sensitivity in detection while being highly cost effective.

Abstract: A microfluidic device is provided with appropriate integrated structures to conduct large volume PCR and end-point or real-time capillary electrophoresis detection The microfluidic device includes a substrate having an amplification chamber of a volume of nucleic acid, wells disposed on the substrate, flow channels connecting the wells and the chamber in the substrate to allow for solution flow through the chamber, and one or more separation channels provided in the substrate and connected to the chamber for separating and detecting a fraction of the amplified nucleic acid The chamber, the flow channels, and the one or more separation channels are configured such that the hydrodynamic flow resistance of the chambers and the flow channels combined is at least 10?3 times smaller than the hydrodynamic flow resistance in the one or more separation channels The microfluidic device can achieve a very high sensitivity in detection while being highly cost effective

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

Abstract: A method and system for providing a cell support system are described. The method and system include providing a first block, a second block coupled to the first block, and a plurality of microfluidic channels. The first block includes a plurality of cell wells therein. The second block includes a plurality of through holes therethrough. The plurality of holes are in fluid communication with at least one corresponding cell well of the plurality of cell wells. The plurality of microfluidic channels are in fluid combination with at least a portion of the plurality of cell wells and are configured to provide an active fluid flow with the portion of the plurality of cell wells.

Abstract: Internal standard concentration is normalized as an independent parameter through measuring a buffer conductance in a system with characterized reagents and in a defined assay device. The conductivity of a fresh internal standard solution is measured whether in isolation or as part of a system that is subject to a uniform variation such as evaporation or condensation. Collected conductance measurements may be used to normalize assay signals that are dependent upon fluidic channel dimensions, such as fluorescence assay signal measurement.

Abstract: To improve cleansing quality of wall surfaces of micro-flow channels in a micro-flow channel cleansing method. During cleansing of wall surfaces of micro-flow channels having at least one branching channel, by causing cleansing fluid to flow therethrough, the cleansing fluid is caused to flow through the at least one branching channel such that there is no residual fluid on the wall surfaces thereof.

Abstract: The invention provides related apparatus and methods of making an integrated electrospray tip by depositing ionic and/or electronic conductor materials onto a planar substrate. The invention also features methods of forming an electrospray apparatus comprising coupling a first planar substrate to the surface of a second planar substrate, wherein a surface on at least one of the substrates includes one or more microfluidic channels and/or reservoirs which are at least partially or totally enclosed therebetween. The conductive regions of the apparatus do not intersect the microfluidic channels within other portions of the apparatus provided preferably. The invention further provides related apparatus and methods for manufacturing and using microfluidic devices with integrated electrodes for electrospray ionization.

Abstract: The invention provides related apparatus and methods of making an integrated electrospray tip by depositing ionic and/or electronic conductor materials onto a planar substrate. The invention also features methods of forming an electrospray apparatus comprising coupling a first planar substrate to the surface of a second planar substrate, wherein a surface on at least one of the substrates includes one or more microfluidic channels and/or reservoirs which are at least partially or totally enclosed therebetween. The conductive regions of the apparatus do not intersect the microfluidic channels within other portions of the apparatus provided preferably. The invention further provides related apparatus and methods for manufacturing and using microfluidic devices with integrated electrodes for electrospray ionization.

Abstract: Microfluidic devices and systems for affecting the serial to parallel conversion of materials introduced into the device or system. Material or materials to be converted from a serial orientation, e.g., a single channel, into a parallel orientation, e.g., multiple channels, are introduced into an open chamber or field in which containing flows of materials maintain the cohesiveness of the sample material plugs serially introduced into the open chamber. The sample material or materials are then redirected in the chamber toward and into a plurality of parallel channels that also communicate with the chamber.

Abstract: A method to achieve controlled conductivity in microfluidic devices, and a device formed thereby. The method comprises forming a microchannel or a well in an insulating material, and ion implanting at least one region of the insulating material at or adjacent the microchannel or well to increase conductivity of the region.

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

Abstract: Methods and systems for use in separating sample materials into different fractions employing pressure-based fluid flow for simultaneous loading of a sample and a reagent into a sample loading channel of a microfluidic device. The sample is loaded from an external source through an attached external sampling capillary. The reagent, which may be a molecular weight standard, a diluent, a detergent, or a labeling reagent, is loaded from a reservoir integral to the microfluidic device via a reagent introduction channel within the device. The sample and reagent form a mixture in the sample loading channel. A portion of the mixture is electrokinetically injected from the sample loading channel, via an injection channel, into a separation channel, where it is separated electrophoretically.

Abstract: The invention provides related apparatus and methods of making an integrated electrospray tip by depositing ionic and/or electronic conductor materials onto a planar substrate. The invention also features methods of forming an electrospray apparatus comprising coupling a first planar substrate to the surface of a second planar substrate, wherein a surface on at least one of the substrates includes one or more microfluidic channels and/or reservoirs which are at least partially or totally enclosed therebetween. The conductive regions of the apparatus do not intersect the microfluidic channels within other portions of the apparatus provided preferably. The invention further provides related apparatus and methods for manufacturing and using microfluidic devices with integrated electrodes for electrospray ionization.

Abstract: A method to achieve controlled conductivity in microfluidic devices, and a device formed thereby. The method comprises forming a microchannel or a well in an insulating material, and ion implanting at least one region of the insulating material at or adjacent the microchannel or well to increase conductivity of the region.

Abstract: Methods and apparatus for providing improved sample injection systems and microfluidic devices with structures such as microchambers that can provide relatively large sample volumes. The microchambers can be formed with a geometry to define sample plugs that can be symmetrical from the perspective of a sample load channel and a sample waste channel. Upon selective application of electrical fields, a defined amount of sample can be injected or loaded from a sample channel into the relatively larger interior volume of a sample chamber prior to ejection into a separation channel so that a sample volume can be separated electrophoretically.

Abstract: A microfluidic chip formed with multiple fluid channels terminating at a tapered electrospray ionization tip for mass spectrometric analysis. The fluid channels may be formed onto a channel plate that are in fluid communication with corresponding reservoirs. The electrospray tip can be formed along a defined distal portion of the channel plate that can include a single or multiple tapered surfaces. The fluid channels may terminate at an open-tip region of the electrospray tip. A covering plate may substantially enclose most portions of the fluid channels formed on the channel plate except for the open-tip region. Another aspect of the invention provides methods for conducting mass spectrometric analysis of multiple samples flowing through individual fluid channels in a single microfluidic chip that is formed with a tapered electrospray tip having an open-tip region.

Abstract: The invention provides related apparatus and methods of making an integrated electrospray tip by depositing ionic and/or electronic conductor materials onto a planar substrate. The invention also features methods of forming an electrospray apparatus comprising coupling a first planar substrate to the surface of a second planar substrate, wherein a surface on at least one of the substrates includes one or more microfluidic channels and/or reservoirs which are at least partially or totally enclosed therebetween. The conductive regions of the apparatus do not intersect the microfluidic channels within other portions of the apparatus provided preferably. The invention further provides related apparatus and methods for manufacturing and using microfluidic devices with integrated electrodes for electrospray ionization.

Abstract: Methods are disclosed for coating at least a portion of a hydrophobic surface, including the surfaces of plastics or other polymers. Such methods include the use of a first coating layer and/or region that interacts with the hydrophobic surface, although the formation of a chemical bond between the first coating layer and the hydrophobic surface is not required. Subsequent layers may then interact chemically or non-chemically with at least a portion of the first coating layer and/or region. Such coated surfaces may be part of a device or apparatus, including microfluidic devices.