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:
Microfluidic devices provide substances to a mass spectrometer. The microfluidic devices include first and second surfaces, at least one microchannel formed by the surfaces, and an outlet at an edge of the surfaces. Some embodiments also include a tip surface with one or more surface features for helping guide substances from the outlet of the device toward a mass spectrometer. In some embodiments, the surface feature(s) includes a groove, which may be hydrophilic along all or part of its length. Hydrophilic surfaces and/or hydrophobic surfaces may also help guide substances out of the outlet and/or toward the mass spectrometer. In some embodiments, the outlet and/or the tip surface is recessed back from an adjacent portion of the edge. A source of electrical potential can help move substances through the microchannel, separate substances and/or provide electrospray ionization.
Abstract:
Microfluidic devices provide substances to a mass spectrometer. The microfluidic devices include first and second surfaces, at least one microchannel formed by the surfaces, and an outlet at an edge of the surfaces. Some embodiments also include a tip surface with one or more surface features for helping guide substances from the outlet of the device toward a mass spectrometer. In some embodiments, the surface feature(s) includes a groove, which may be hydrophilic along all or part of its length. Hydrophilic surfaces and/or hydrophobic surfaces may also help guide substances out of the outlet and/or toward the mass spectrometer. In some embodiments, the outlet and/or the tip surface is recessed back from an adjacent portion of the edge. A source of electrical potential can help move substances through the microchannel, separate substances and/or provide electrospray ionization.
Abstract:
The present invention provides microfluidic devices and methods that are useful for performing high-throughput screening assays. In particular, the devices and methods of the invention are useful in screening large numbers of different compounds for their effects on a variety of chemical, and preferably, biochemical systems. The device includes a series of channels (110, 112), and optional reagent channel (114), fabricated into the surface of the substrate. At least one of these channels will typically have very small cross-sectional dimensions, e.g. in the range of from about 0.1 mu m to about 500 mu m. The device also includes reservoirs (104, 106 and 108), disposed and fluidly connected at the ends of the channels (110 and 114). As shown, sample channel (112) is used to introduce the plurality of different test compounds into the device. As such, this channel will generally be fluidly connected to a source of large numbers of separate test compounds that will be individually introduced into the sample channel (112) and subsequently into channel (110).
Abstract:
Methods, devices, and systems for performing isoelectric focusing reactions are described. The systems or devices disclosed herein may comprise fixtures that have a membrane. In some instances, the disclosed devices may be designed to perform isoelectric focusing or other separation reactions followed by further characterization of the separated analytes using mass spectrometry. Two or more isoelectric focusing reactions may be performed in parallel. The disclosed methods, devices, and systems provide for fast, accurate separation and characterization of protein analyte mixtures or other biological molecules by isoelectric point.
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 10Λ3 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:
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:
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:
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:
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.