"Two-site" or "sandwich" immunometric assay techniques for determination of the presence and/or concentration of antigenic substances in fluids using monoclonal antibodies are described and compared to conventional assays using polyclonal antibodies. Also described are inhibition assays using complexes of antigens with a monoclonal antibody.

Immunometric assays using monoclonal antibodies

The invention provides methods of detecting a nucleic acid. The methods comprise contacting the nucleic acid with one or more types of particles having oligonucleotides attached thereto. In one embodiment of the method, the oligonucleotides are attached to nanoparticles and have sequences complementary to portions of the sequence of the nucleic acid. A detectable change (preferably a color change) is brought about as a result of the hybridization of the oligonucleotides on the nanoparticles to the nucleic acid. The invention also provides compositions and kits comprising particles. The invention further provides methods of synthesizing unique nanoparticle-oligonucleotide conjugates, the conjugates produced by the methods, and methods of using the conjugates. In addition, the invention provides nanomaterials and nanostructures comprising nanoparticles and methods of nanofabrication utilizing nanoparticles. Finally, the invention provides a method of separating a selected nucleic acid from other nucleic acids.

Nanoparticles having oligonucleotides attached thereto and uses therefor

Unimolecular and bimolecular hybridization probes for the detection of nucleic acid target sequences comprise a target complement sequence, an affinity pair holding the probe in a closed conformation in the absence of target sequence, and either a label pair that interacts when the probe is in the closed conformation or, for certain unimolecular probes, a non-interactive label. Hybridization of the target and target complement sequences shifts the probe to an open conformation. The shift is detectable due to reduced interaction of the label pair or by detecting a signal from a non-interactive label. Certain unimolecular probes can discriminate between target and non-target sequences differing by as little as one nucleotide. Also, universal stems and kits useful for constructing said probes. Also, assays utilizing said probes and kits for performing such assays. Also, such probes capable of allelic discrimination.

Detectably labeled dual conformation oligonucleotide probes, assays and kits

Methods for high speed, high throughput analysis of polynucleotide sequences, and apparatuses with which to carry out the methods are provided in the invention.

Methods and apparatuses for analyzing polynucleotide sequences

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation—when excited by an electromagnetic radiation source or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affinity molecule. The compound is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. subsequent exposure to excitation energy will excite the semiconductor nanocrystal in the probe causing the emission of electromagnetic radiation. Further described are processes for respectively: making the luminescent semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

Immunoassays employing antibodies and a fluorescer-quencher (F-Q) chromophoric pair, wherein one or both of the chromophoric pair are bonded to antibodies. Depending on the particular ligand of interest, various reagent combinations can be employed, where the amount of quenching is directly related to the amount of ligand present in the assay medium. In carrying out the assay, the unknown and antibody specific for the ligand of interest to which is bound one of the F-Q pair, are combined in an aqueous buffered medium. Depending on the protocol, different assay reagents are employed in the aqueous buffered medium: (1) ligand analog bonded to the other of the F-Q pair; (2) antibodies specific for the ligand to which is bound the other of the F-Q pair or; finally, (3) a combination of a plurality of ligands bonded together through linking groups to a hub molecule, usually a polymer, in combination with antibody bound to the other of the F-Q pair. The composition is irradiated with light at a wavelength, absorbed by the fluorescing molecule and the amount of fluorescence determined. By employing appropriate standards, the presence and amount of the ligand can be determined.

Moshe Schwarzberg

Papers

Fluorescence quenching with immunological pairs in immunoassays

Fluorescence quenching system