Abstract: A method is provided for preparing luminescent semiconductor nanoparticles composed of a first component X, a second component A, and a third component B, wherein X, A, and B are different, by combining B with X and A in an amount such that the molar ratio B:(A+B) is in the range of approximately 0.001 to 0.20 and the molar ratio X:(A+B) is in the range of approximately 0.5:1.0 to 2:1. The characteristics of the thus-prepared nanoparticles can be substantially similar to those of nanoparticles containing only X and B while maintaining many useful properties characteristic of nanoparticles containing only X and A. The nanoparticles so prepared can additionally exhibit emergent properties such as a peak emission energy less than that characteristic of a particle composed of XA or XB alone; this method is particularly applicable to the preparation of stable, bright nanoparticles that emit in the red to infrared regions of the electromagnetic spectrum.

Abstract: Methods, compositions and articles of manufacture for assaying a sample for an amplification product from a target polynucleotide are provided. An amplification reaction is used to produce the amplification product from the target polynucleotide so that it can be used to indirectly assay the sample for the target polynucleotide. A sample suspected of containing the target polynucleotide is contacted with first and second primers to amplify the target polynucleotide; the first primer comprises a tag sequence, the complement of which is formed on the opposite strand during amplification and is referred to as a capture sequence. That opposite strand is referred to as a second primer extension product or an amplification product, and comprises a label. A capture probe is provided that is conjugated to a substrate and can bind to the capture sequence to form an amplification product detection complex.

Abstract: Nanocrystals are synthesized with a high degree of control over reaction conditions and hence product quality in a flow-through reactor in which the reaction conditions are maintained by on-line detection of characteristic properties of the product and by adjusting the reaction conditions accordingly. The coating of nanocrystals is achieved in an analogous manner.

Abstract: Methods for synthesizing luminescent nanoparticles and nanoparticles prepared by such methods are provided. The nanoparticles are prepared by a method in which an additive is included in the reaction mixture. The additive may be a Group 2 element, a Group 12 element, a Group 13 element, a Group 14 element, a Group 15 clement, or a Group 16 element. In additions, a luminescent nanoparticle is provided that comprises a semiconductive core surrounded by an inorganic shell, an interfacial region and an additive present in the interfacial region or both the interfacial region and the shell.

Abstract: Improved devices, systems, and methods for sensing and/or identifying signals from within a signal detection region are well-suited for identification of spectral codes. Large numbers of independently identifiable spectral codes can be generated by quite small bodies, and a plurality of such bodies or probes may be present within a detection region. Simultaneously imaging of identifiable spectra from throughout the detection region allows the probes to be identified. As the identifiable spectra can be treated as being generated from a point source within a much larger detection field, a prism, diffractive grading, holographic transmissive grading, or the like can spectrally disperse the images of the labels across a sensor surface. A CCD can identify the relative wavelengths of signals making up the spectra. Absolute signal wavelengths may be identified by determining positions of the labels, by an internal wavelength reference within the spectra, or the like.

Abstract: Devices, systems, methods, and compositions of matter can track and/or identify a library of elements, particularly for use with fluids, particulates, cells, and the like. Signals from one or more semiconductor nanocrystals may be combined to define spectral codes. Separation of signal wavelengths within dedicated wavelength ranges or windows facilitates differentiation of spectral codes, while calibration signals within the spectral codes can avoid ambiguity. Modeling based on prior testing can help derive libraries of acceptable codes.

Abstract: Methods, compositions and articles of manufacture for assaying a sample for a target polynucleotide and/or an amplification product therefrom are provided. The methods comprise contacting a sample suspected of containing the target polynucleotide with a polynucleotide that can bind specifically thereto; this polynucleotide is conjugated to a substrate, preferably an encoded bead conjugate. An amplification reaction can first be used to produce the amplification product from the target polynucleotide so that it can be used to indirectly assay for the target polynucleotide. An amplification product detection complex and method of forming the same are also provided. The methods are particularly useful in multiplex settings where a plurality of targets are present. Amplification product assay complexes and amplification product assay arrays are also provided, along with methods of forming the same. Kits comprising reagents for performing such methods are also provided.

Abstract: The use of semiconductor nanocrystals as detectable labels in various chemical and biological applications is disclosed. The methods find use for detecting a single analyte, as well as multiple analytes by using more than one semiconductor nanocrystal as a detectable label, each of which emits at a distinct wavelength.

Abstract: Improved devices, systems, and methods for sensing and/or identifying signals from within a signal detection region are well-suited for identification of spectral codes. Large numbers of independently identifiable spectral codes can be generated by quite small bodies, and a plurality of such bodies or probes may be present within a detection region. Simultaneously imaging of identifiable spectra from throughout the detection region allows the probes to be identified. As the identifiable spectra can be treated as being generated from a point source within a much larger detection field, a prism, diffractive grading, holographic transmissive grading, or the like can spectrally disperse the images of the labels across a sensor surface. A CCD can identify the relative wavelengths of signals making up the spectra. Absolute signal wavelengths may be identified by determining positions of the labels, by an internal wavelength reference within the spectra, or the like.

Abstract: Devices, systems, methods, and compositions of matter can track and/or identify a library of elements, particularly for use with fluids, particulates, cells, and the like. Signals from one or more semiconductor nanocrystals may be combined to define spectral codes. Separation of signal wavelengths within dedicated wavelength ranges or windows facilitates differentiation of spectral codes, while calibration signals within the spectral codes can avoid ambiguity. Modeling based on prior testing can help derive libraries of acceptable codes.

Abstract: Nanocrystals are synthesized with a high degree of control over reaction conditions and hence product quality in a flow-through reactor in which the reaction conditions are maintained by on-line detection of characteristic properties of the product and by adjusting the reaction conditions accordingly. The coating of nanocrystals is achieved in an analogous manner.

Abstract: Methods, compositions and articles of manufacture for assaying a sample for a target polynucleotide and/or an amplification product therefrom are provided. The methods comprise contacting a sample suspected of containing the target polynucleotide with a polynucleotide that can bind specifically thereto; this polynucleotide is conjugated to a substrate, preferably an encoded bead conjugate. An amplification reaction can first be used to produce the amplification product from the target polynucleotide so that it can be used to indirectly assay for the target polynucleotide. An amplification product detection complex and method of forming the same are also provided. The methods are particularly useful in multiplex settings where a plurality of targets are present. Amplification product assay complexes and amplification product assay arrays are also provided, along with methods of forming the same. Kits comprising reagents for performing such methods are also provided.

Abstract: Water-dispersible nanoparticles are prepared by applying a coating of a multiply amphipathic dispersant to the surface of a hydrophobic nanoparticle comprised of a semiconductive or metallic material. The multiply amphipathic dispersant has two or more hydrophobic regions and two or more hydrophilic regions, and is typically polymeric. Preferred polymeric dispersants are comprised of (1) a hydrophobic backbone with hydrophilic branches, (2) a hydrophilic backbone with hydrophobic branches, or (3) a backbone that may be either hydrophobic or hydrophilic, and substituted with both hydrophilic and hydrophobic branches. Monodisperse populations of water-dispersible nanoparticles are also provided, as are conjugates of the water-dispersible nanoparticles with affinity molecules such as peptides, oligonucleotides, and the like.

Abstract: The use of semiconductor nanocrystals as detectable labels in various chemical and biological applications is disclosed. The methods find use for detecting a single analyte, as well as multiple analytes by using more than one semiconductor nanocrystal as a detectable label, each of which emits at a distinct wavelength.

Abstract: Methods, compositions and articles of manufacture for assaying a sample for a target polynucleotide and/or an amplification product therefrom are provided. The methods comprise contacting a sample suspected of containing the target polynucleotide with a polynucleotide that can bind specifically thereto; this polynucleotide is conjugated to a substrate, preferably an encoded bead conjugate. An amplification reaction can first be used to produce the amplification product from the target polynucleotide so that it can be used to indirectly assay for the target polynucleotide. An amplification product detection complex and method of forming the same are also provided. The methods are particularly useful in multiplex settings where a plurality of targets are present. Amplification product assay complexes and amplification product assay arrays are also provided, along with methods of forming the same. Kits comprising reagents for performing such methods are also provided.

Abstract: Methods, compositions and articles of manufacture for assaying a sample for a target polynucleotide and/or an amplification product therefrom are provided. The methods comprise contacting a sample suspected of containing the target polynucleotide with a polynucleotide that can bind specifically thereto; this polynucleotide is conjugated to a substrate, preferably an encoded bead conjugate. An amplification reaction can first be used to produce the amplification product from the target polynucleotide so that it can be used to indirectly assay for the target polynucleotide. An amplification product detection complex and method of forming the same are also provided. The methods are particularly useful in multiplex settings where a plurality of targets are present. Amplification product assay complexes and amplification product assay arrays are also provided, along with methods of forming the same. Kits comprising reagents for performing such methods are also provided.

Abstract: Nanocrystals are synthesized with a high degree of control over reaction conditions and hence product quality in a flow-through reactor in which the reaction conditions are maintained by on-line detection of characteristic properties of the product and by adjusting the reaction conditions accordingly. The coating of nanocrystals is achieved in an analogous manner.

Abstract: Improved devices, systems, and methods for sensing and/or identifying signals from within a signal detection region are well-suited for identification of spectral codes. Large numbers of independently identifiable spectral codes can be generated by quite small bodies, and a plurality of such bodies or probes may be present within a detection region. Simultaneously imaging of identifiable spectra from throughout the detection region allows the probes to be identified. As the identifiable spectra can be treated as being generated from a point source within a much larger detection field, a prism, diffractive grading, holographic transmissive grading, or the like can spectrally disperse the images of the labels across a sensor surface. A CCD can identify the relative wavelengths of signals making up the spectra. Absolute signal wavelengths may be identified by determining positions of the labels, by an internal wavelength reference within the spectra, or the like.

Abstract: The present invention provides assays that allow for the detection of a single copy of a target of interest. The target species is either directly or indirectly labeled with a semiconductor nanocrytal, “quantum dot.” The bright and tunable fluorescence of the quantum dot is readily detected using methods described herein. Also provided are assays that are based on the colocalization of two or more differently colored quantum dots on a single target species, which provides superbly sensitive assays in which the decrease in assay sensitivity caused by non-specific binding of assay mixture components to the assay substrate is minimized. The assays are of use to detect target species including, but are not limited to, nucleic acids, polypeptides, small organic bioactive agents (e.g., drugs, agents of war, herbicides, pesticides, etc.) and organisms.

Abstract: Methods for assaying a sample for a probe polynucleotide are provided. The methods comprise forming a complex between a target on a substrate, the probe polynucleotide that binds to the target, and a conjugate comprising a semiconductor nanocrystal that binds to the probe polynucleotide by way of a tag sequence on the probe polynucleotide. The complex is formed when the probe polynucleotide is present in the sample. The methods are useful in any technique in which the detection of a target that can bind to a probe polynucleotide is desired, for example in fluorescence in situ hybridization. The methods are particularly useful in multiplex settings such as hybridization to microarrays where a plurality of targets are present. Assay complexes produced by such methods and kits useful for performing such methods are also provided.