The present invention provides novel microfluidic devices and methods that are useful for performing high-throughput screening assays and combinatorial chemistry. The invention provides for aqueous based emulsions containing uniquely labeled cells, enzymes, nucleic acids, etc., wherein the emulsions further comprise primers, labels, probes, and other reactants. An oil based carrier-fluid envelopes the emulsion library on a microfluidic device, such that a continuous channel provides for flow of the immiscible fluids, to accomplish pooling, coalescing, mixing, sorting, detection, etc., of the emulsion library.

Disclosed are methods of multiplexed analysis of oligonucleotides in a sample, including: methods of probe and target engineering, as well as methods of assay signal analysis relating to the modulation of the probe-target affinity constant, K by a variety of factors including the elastic properties of target strands and layers of immobilized (grafted) probes; and assay methodologies relating to: the tuning of assay signal intensities including dynamic range compression and on-chip signal amplification; the combination of hybridization-mediated and elongation-mediated detection for the quantitative determination of abundance of messages displaying a high degree of sequence similarity, including, for example, the simultaneous determination of the relative expression levels, and identification of the specific class of, untranslated AU-rich subsequences located near the 3 terminus of mRNA; and a new method of subtractive differential gene expression analysis which requires only a single color label.

A microsphere-based analytic chemistry system and method for making the same is disclosed in which microspheres or particles carrying bioactive agents may be combined randomly or in ordered fashion and dispersed on a substrate to form an array while maintaining the ability to identify the location of bioactive agents and particles within the array using an optically interrogatable, optical signature encoding scheme. A wide variety of modified substrates may be employed which provide either discrete or non-discrete sites for accommodating the microspheres in either random or patterned distributions. The substrates may be constructed from a variety of materials to form either two-dimensional or three-dimensional configurations. In a preferred embodiment, a modified fiber optic bundle or array is employed as a substrate to produce a high density array. The disclosed system and method have utility for detecting target analytes and screening large libraries of bioactive agents.

A microsphere-based analytic chemistry system and method for making the same is disclosed in which microspheres or particles carrying bioactive agents may be combined randomly or in ordered fashion and dispersed on a substrate to form an array while maintaining the ability to identify the location of bioactive agents and particles within the array using an optically interrogatable, optical signature encoding scheme. A wide variety of modified substrates may be employed which provide either discrete or non-discrete sites for accommodating the microspheres in either random or patterned distributions. The substrates may be constructed from a variety of materials to form either two-dimensional or three-dimensional configurations. In a preferred embodiment, a modified fiber optic bundle or array is employed as a substrate to produce a high density array. The disclosed system and method have utility for detecting target analytes and screening large libraries of bioactive agents.

A sample plate comprising a sample well is disclosed. The sample well can comprise one or more bead retaining chambers. A method of using the sample plate and a kit comprising the sample plate is also disclosed.

An array of transportable particle sets is used in a microfluidic device for performing chemical reactions in the microfluidic device. The microfluidic device comprises a main channel and intersecting side channels, the main channel and side channels forming a plurality of intersections. The array of particle sets is disposed in the main channel, and the side channels are coupled to reagents. As the particle sets are transported through the intersections of the main channel and the side channels, reagents are flowed through the side channels into contact with each array member (or selected array members), thereby providing a plurality of chemical reactions in the microfluidic system.

Disclosed are methods of multiplexed analysis of oligonucleotides in a sample, including a method of preventing a significant reduction in duplexes detectable in a hybridization assay involving (i) selecting probe lengths for sets of oligonucleotide probes, wherein probes include different subsequences such that at least one subsequence is complementary to a subsequence in a cognate target; wherein probes for longer cognate targets are longer in length than probes for shorter cognate targets, (ii) selecting, for each set of probes, a density of oligonucleotides probes attached per unit area on a solid phase carrier which is below a limit at which the significant reduction in detectable duplexes is predicated to take place, (iii) producing the probes and affixing them to different solid phase carriers at the selected density, and (iv) annealing targets to the probes, wherein signal intensities of probes and targets of different lengths are about the same.

Disclosed are methods of multiplexed analysis of oligonucleotides in a sample, including a method of preventing a significant reduction in duplexes detectable in a hybridization assay involving (i) selecting probe lengths for sets of oligonucleotide probes, wherein probes include different subsequences such that at least one subsequence is complementary to a subsequence in a cognate target; wherein probes for longer cognate targets are longer in length than probes for shorter cognate targets, (ii) selecting, for each set of probes, a density of oligonucleotides probes attached per unit area on a solid phase carrier which is below a limit at which the significant reduction in detectable duplexes is predicated to take place, (iii) producing the probes and affixing them to different solid phase carriers at the selected density, and (iv) annealing targets to the probes, wherein signal intensities of probes and targets of different lengths are about the same.

The present invention provides novel microfluidic devices and methods that are useful for performing high-throughput screening assays and combinatorial chemistry. The invention provides for aqueous based emulsions containing uniquely labeled cells, enzymes, nucleic acids, etc., wherein the emulsions further comprise primers, labels, probes, and other reactants. An oil based carrier-fluid envelopes the emulsion library on a microfluidic device, such that a continuous channel provides for flow of the immiscible fluids, to accomplish pooling, coalescing, mixing, sorting, detection, etc., of the emulsion library.

An apparatus includes a device substrate including an array of sensors. Each sensor of the array of sensors can include a electrode structure disposed at a surface of the device substrate. The apparatus further includes a wall structure overlying the surface of the device substrate and defining an array of wells at least partially corresponding with the array of sensors. The well structure including an electrode layer and an insulative layer.