Abstract: Methods and systems are provided for accurate and efficient identification and quantification of proteins. In an aspect, disclosed herein is a method for identifying a protein in a sample of unknown proteins, comprising receiving information of a plurality of empirical measurements performed on the unknown proteins; comparing the information of empirical measurements against a database comprising a plurality of protein sequences, each protein sequence corresponding to a candidate protein among a plurality of candidate proteins; and for each of one or more of the plurality of candidate proteins, generating a probability that the candidate protein generates the information of empirical measurements, a probability that the plurality of empirical measurements is not observed given that the candidate protein is present in the sample, or a probability that the candidate protein is present in the sample; based on the comparison of the information of empirical measurements against the database.

Abstract: Systems and methods for obtaining qualitative or quantitative measurements of proteoforms of polypeptides are described. The described methods include measurements of affinity reagent binding on single-molecule polypeptide arrays to distinguish between polypeptide isoforms. The described methods may provide high resolution quantitative comparisons of proteoforms with very low copy numbers.

Abstract: Compositions, systems, and methods are disclosed for preparing and utilizing arrays, such as single-analyte arrays containing a plurality of fiducial elements with random spatial distributions. Arrays may be prepared with pluralities of fiducial elements comprising optically active or passive moieties. Arrays containing random spatial distributions of fiducial elements may be utilized for various array-based processes that require spatial information.

Abstract: Compositions, systems, and methods for the display of analytes such as biomolecules are described. Display of analytes is achieved by coupling of the analytes to displaying molecules that are configured to associate with surfaces or interfaces. Arrays of analytes may be formed from the described systems for utilization in assays and other methods.

Abstract: Methods and systems are provided herein for selecting an affinity reagent which binds a desired peptide epitope in a plurality of sequence contexts. The method relies on obtaining a peptide library, each peptide having the sequence ?X?, wherein X is the desired peptide epitope, wherein each of ? and ? comprise an amino acid, using the peptide library to select an affinity reagent.

Abstract: An affinity reagent, having: (a) a retaining component such as a structured nucleic acid particle; and (b) one or both of (i) one or more label components attached to the retaining component, and (ii) one or more binding components attached to the retaining component.

Abstract: Methods and systems are provided herein for selecting an affinity reagent which binds a desired peptide epitope in a plurality of sequence contexts. The method relies on obtaining a peptide library, each peptide having the sequence ?X?, wherein X is the desired peptide epitope, wherein each of ? and ? comprise an amino acid, using the peptide library to select an affinity reagent.

Abstract: The present disclosure provides systems and methods for detecting components of an array of biological, chemical, or physical entities. In an aspect, the present disclosure provides a method for detecting an array of biological, chemical, or physical entities, comprising: (a) using one or more light sensing devices, acquiring pixel information from sites in an array, wherein the sites comprise biological, chemical, or physical entities that produce light; (b) processing the pixel information to identify a set of regions of interest (ROIs) corresponding to the sites in the array that produce the light; (c) classifying the pixel information for the ROIs into a categorical classification from among a plurality of distinct categorical classifications, thereby producing a plurality of pixel classifications; and (d) identifying one or more components of the array of biological, chemical, or physical entities based at least in part on the plurality of pixel classifications.

Abstract: Compositions, systems, and methods for the display of analytes such as biomolecules are described. Display of analytes is achieved by coupling of the analytes to displaying molecules that are configured to associate with surfaces or interfaces. Arrays of analytes may be formed from the described systems for utilization in assays and other methods.

Abstract: Methods and systems for identifying a protein within a sample are provided herein. A panel of antibodies are acquired, none of which are specific for a single protein or family of proteins. Additionally, the binding properties of the antibodies in the panel are determined. Further, the protein is iteratively exposed to a panel of antibodies. Additionally, a set of antibodies which bind the protein are determined. The identity of the protein is determined using one or more deconvolution methods based on the known binding properties of the antibodies to match the set of antibodies to a sequence of a protein.

Abstract: Compositions, systems, and methods for the display of analytes such as biomolecules are described. Display of analytes is achieved by coupling of the analytes to displaying molecules that are configured to associate with surfaces or interfaces. Arrays of analytes may be formed from the described systems for utilization in assays and other methods.

Abstract: Methods and systems for identifying a protein within a sample are provided herein. A panel of antibodies are acquired, none of which are specific for a single protein or family of proteins. Additionally, the binding properties of the antibodies in the panel are determined. Further, the protein is iteratively exposed to a panel of antibodies. Additionally, a set of antibodies which bind the protein are determined. The identity of the protein is determined using one or more deconvolution methods based on the known binding properties of the antibodies to match the set of antibodies to a sequence of a protein.

Abstract: Methods and systems are provided for accurate and efficient identification and quantification of proteins. In an aspect, disclosed herein is a method for identifying a protein in a sample of unknown proteins, comprising receiving information of a plurality of empirical measurements performed on the unknown proteins; comparing the information of empirical measurements against a database comprising a plurality of protein sequences, each protein sequence corresponding to a candidate protein among a plurality of candidate proteins; and for each of one or more of the plurality of candidate proteins, generating a probability that the candidate protein generates the information of empirical measurements, a probability that the plurality of empirical measurements is not observed given that the candidate protein is present in the sample, or a probability that the candidate protein is present in the sample; based on the comparison of the information of empirical measurements against the database.

Abstract: An affinity reagent, having: (a) a retaining component such as a structured nucleic acid particle; and (b) one or both of (i) one or more label components attached to the retaining component, and (ii) one or more binding components attached to the retaining component.