Disclosed herein, inter alia, are compositions and methods of use thereof for interrogating a cell.

The present invention is generally directed to compositions, methods, and systems for performing single-molecule, real-time analysis of a variety of different biological reactions, and for determining various characteristics of the different biological reactions. The ability to analyze such reactions provides an opportunity to study those reactions as well as to potentially identify factors and/or approaches for impacting such reactions, e.g., to stimulate, enhance, or inhibit such reactions.

The present invention relates to a method for detecting a spatial proximity of a first and a second epitope (11, 21) of a protein or of a first and a second protein (10, 20) of a protein complex (1) in a sample of a subject. The method comprises binding a first binding member (30) having a first oligonucleotide (31) conjugated thereto to the first epitope (11), binding a second binding member (40) having a second oligonucleotide (41) conjugated thereto to the second epitope (21), and determining whether a Fluorescence Resonance Energy Transfer (FRET) effect is present between a donor fluorophore (32) and an acceptor fluorophore (42), which are associated with the first oligonucleotide (31) and the second oligonucleotide (41), wherein the presence of the FRET effect indicates a spatial proximity of the first and the second oligonucleotide (31, 41) and, thus, the spatial proximity of the first and the second epitope (11, 21).

Provided herein is a method and system for analyzing a sample. In some embodiments the method makes use of a plurality of capture agents that are each linked to a different oligonucleotide and a corresponding plurality of labeled nucleic acid probes, wherein each of the labeled nucleic acid probes specifically hybridizes with only one of the oligonucleotides. The sample is labeled with the capture agents en masse, and sub-sets of the capture agents are detected using iterative cycles using corresponding subsets of the labeled nucleic acid probes.

Some embodiments of the disclosure provide a time-resolved fluorescent immunochromatographic test strip for detecting paclitaxel drugs as well as a preparation method and application thereof. In some embodiments, the test strip includes a test paper and a sample diluent. The test paper includes a bottom plate, a sample absorption pad, a fluorescent microsphere pad, a bonding pad, and an absorbent pad. The sample absorption pad, the fluorescent microsphere pad, the bonding pad, and the absorbent pad are sequentially overlapped on the bottom plate. The fluorescent microsphere pad is sprayed with a fluorescent microsphere-labeled anti-paclitaxel monoclonal antibody. A detection area and a quality control area are immobilized on the bonding pad. The detection area is sprayed with a paclitaxel hapten-carrier protein conjugate. The quality control area is sprayed with a goat anti mouse antibody.

The present invention relates generally methods and kits for detecting binding interactions, in particular protein-protein interactions, and particularly to high throughput methods for labelling, analysing, detecting and measuring protein-protein interactions.

Provided herein are methods and compositions for single cell characterization using affinity-oligonucleotide conjugates. Provided herein are methods and compositions for single cell characterization using tetramer-oligonucleotide conjugates.

Methods and reagents for detection and analysis of nucleic acids are provided. The methods employ proximity extension assays for detection of a target nucleic acids of interest, e.g., a target RNA. The method can additionally be used in multiplex assays with a protein proximity extension assay to detect protein.

Embodiments of the invention provides a method for detection of at least one analyte derived from a sample, comprising the steps of: a) depositing the sample on a surface of a solid support; b) transferring at least a portion of the solid support to a receptacle suitable for performing a specific binding assay for one or more analytes of interest; c) optionally washing the portion; d) adding a single specific binding partner for each analyte of interest to the receptacle, the binding partner being labelled with an oligonucleotide sequence; e) mixing the portion with nucleic acid amplification reagents; f) amplifying the oligonucleotide sequence; and g) detecting amplified nucleic acid. The invention also provides a kit for use with the method for detection of at least one analyte derived from a sample.

This disclosure related to methods of detecting mechanical forces required to separate ligand and receptor interactions. In certain embodiments, this disclosure relates to methods of detecting mechanical forces between a ligand and receptor, where the ligand is immobilized on a surface using weaker forces. Ligand-receptor forces lead to dissociation of the ligand that can be detected and amplified. In certain embodiments, the disclosure relates to methods of detecting ligand and receptor interactions comprising linking a ligand to one of two binding partners, wherein the binding partners have attracting forces that are less than the forces between the ligand and a receptor of the ligand such that when the ligand binds the receptor, the binding partners will separate. Separation of the binding partners can be detected.