METHODS FOR TARGETED PROTEIN QUANTIFICATION BY BAR-CODING AFFINITY REAGENT WITH UNIQUE DNA SEQUENCES

Information

  • Patent Application
  • 20240309041
  • Publication Number
    20240309041
  • Date Filed
    May 28, 2024
    6 months ago
  • Date Published
    September 19, 2024
    3 months ago
Abstract
Provided herein are affinity reagents having affinity for particular target, each reagent having a unique DNA barcode, and methods for using the same to measure the abundance of targets in a sample. In particular, methods are provided in which unique barcodes linked to affinity reagents are contacted to a sample to bind antigens if present in said sample. In cases in which the affinity reagents are antibodies and the targets are antigens, antibodies that are bound to their target antigens can be separated from unbound antibodies and the DNA barcode associated with the affinity reagent is amplified, such as with a PCR reaction. In some cases, amplified barcode DNA is subjected to DNA sequencing as a measure of the levels of the target protein in the sample.
Description
REFERENCE TO AN ELECTRONIC SEQUENCE LISTING

The contents of the electronic sequence listing (112624.01454.xml: Size: 258,150 bytes: and Date of Creation: May 24, 2024) is herein incorporated by reference in its entirety.


STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not applicable.
BACKGROUND

With the advent of various ‘omics’ technologies and methods which stratify samples and diseases based on measuring many variables simultaneously, there is an increasing demand for high throughput tools that quantify specific targets. There are already numerous genomics tools that assess gene expression, gene copy number, mutations, etc. at a global scale to determine subtypes of disease that might be useful for prognostication and management of therapy. But it is well known that the genome (which is a blue print) does not always reflect the actual state of biology at any time and gene measurements are not always possible from readily accessible samples like blood. Thus, there is a strong desire to have similar high throughput tools to measure the proteome, which is the product of the genome and more closely reflects the current state of biology. However, high throughput measurement of the proteome is much more challenging than similar genome measurements, because there is no protein equivalent to the base pairing measurements that emerge from the inherent double-stranded nature of DNA.


There is a wide variety of methods to measure proteins. These can be generally divided into antibody-based methods and chemistry-based methods. By far, the most common chemistry-based method is mass spectrometry, which is most commonly employed by ionizing peptides (created by proteolytic digestion) and measuring their mobility in a magnetic field. The accuracy of these instruments is sufficient to identify virtually any protein by comparing its spectrum to spectrums predicted from the genome. Although nearly universal in its ability to detect proteins and even modified proteins, mass spectrometry is very low throughput. A thorough examination of single sample can take hours and it requires great care to run a set samples in a fashion that allows comparison of one run to the next. There are many other tools that detect proteins chemically, but they are not capable of identifying specific proteins in a universal manner.


Detection of proteins is most commonly accomplished with antibodies (or more generally, affinity reagents), and include many different configurations such as western blots, immunoprecipitation, flow cytometry, reverse phase protein arrays, enzyme linked immunosorbent assay (ELISA), and many others. These applications all rely on antibodies that recognize specific targets, and which can bind with extraordinary selectivity and affinity. There are currently more than 2,000,000 antibodies available on the market that target a large fraction of the human proteome. It is important to note that not all antibodies are high quality, but many are quite good and methods to produce antibodies have become routine. Although the use of an antibody to measure its target can be relatively fast, it is not straightforward to multiplex measurements using many antibodies simultaneously. Accordingly, there remains a need in the art for improved methods for simultaneous multiplexed detection and measurement of many proteins (including specific post-translational forms of proteins) or other target molecules.


SUMMARY

In a first aspect, provided herein is a composition comprising a plurality of modified affinity reagents, each affinity reagent of the plurality comprising a unique identifying nucleotide sequence relative to other affinity reagents of the plurality, wherein each identifying nucleotide sequence is flanked by a first amplifying nucleotide sequence and a second amplifying nucleotide sequence. Affinity reagents of the plurality can be antibodies. Affinity reagents of the plurality can be peptide aptamers or nucleic acid aptamers. An identifying nucleotide sequence can be attached to an affinity reagent by a linker comprising a cleavable protein photocrosslinker. An identifying nucleotide sequence can be attached to an affinity reagent by a linker comprising a fluorescent moiety. Unique identifying nucleotide sequences of the plurality can comprise one or more of SEQ ID Nos: 104-203.


In another aspect, provided herein is a method for high throughput target molecule identification and quantification. The method can comprise or consist essentially of contacting a sample with a modified affinity reagent under conditions that promote binding of the modified affinity reagent to its target molecule if present in the contacted sample; removing unbound modified affinity reagent from the contacted sample; and amplifying and sequencing an identifying nucleotide sequence coupled to said modified affinity reagent whereby the target molecule is identified and quantified based on detection of the identifying nucleotide sequence. The method can further comprise adding a linker to an affinity reagent to form the modified affinity reagent, wherein the linker comprises the identifying nucleotide sequence flanked by a pair of amplifying nucleotide sequences. The affinity reagent can be an antibody. The adding step can further comprise adding a linker to a region of the antibody that is not an antigen binding region. The adding step can further comprise adding a linker to a fragment crystallizable region (Fc region) of the antibody. The affinity reagent can be an aptamer. The identifying nucleotide sequence can have a length of about 10 nucleotides to about 20 nucleotides. The identifying nucleotide sequence can have a length of about 12 nucleotides. The linker can be selected from SEQ ID Nos: 104-203. The identifying nucleotide sequence can comprise SEQ ID NO:1 or a barcode sequence set forth in Table 1. The identifying nucleotide sequence can comprise about 50% of AT base pairs and about 50% of GC base pairs. The amplifying sequence can have a length ranging from 20 to 30 base pair. The amplifying sequence can comprise SEQ ID NO:2. The amplifying sequence can comprise SEQ ID NO:3. The linker can further comprise a fluorescent protein or a cleavable protein photocrosslinker.


In a further aspect, provided herein is a kit for high throughput protein quantification. The kit can comprise X modified affinity reagent(s), where X is equal to or greater than 1, each modified affinity reagent comprising a linker, where the linker comprising an identifying nucleotide sequence flanked by a pair of amplifying nucleotide sequences; and each modified affinity reagent comprising a different identifying nucleotide sequence from other modified affinity reagents. The linker can be selected from SEQ ID Nos: 104-203.





BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will be better understood and features, aspects, and advantages other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such detailed description makes reference to the following drawings, wherein:



FIG. 1 is a flowchart that illustrates steps of a method for high throughput protein quantification.



FIG. 2 demonstrates cloning and protein expression of the HPV proteome. An SDS-PAGE gel shows the expression of antigens of different HPV subtypes. (*) indicates an unexpressed protein. Further experiments confirmed expression of HPV58 E7, L1, and L2.



FIG. 3 demonstrates immune response screening of OPC patient sera. Percent barcode enrichment of control and OPC patient sera after barcode amplification and next generation sequencing.



FIG. 4 is an image of a DNA gel showing the enrichment of antibodies against E1 and E7 antigens in OPC patient P3 with barcode specific primers.





DETAILED DESCRIPTION

The compositions and methods described herein couples the ability of antibodies (or virtually any affinity reagent) to recognize their targets with a unique DNA barcode that enables the detection of the antibody using, for example, next generation DNA sequencing methods. This disclosure is based at least in part on the inventor's development of a quantitative, multiplexed, bar-coded antigen library for detection and measurement of immune responses in pathogen-induced cancers including, for example, multiple serotypes of HPV (Human Papillomavirus)-positive Oropharyngeal carcinomas (OPC).


Affinity Reagents

Accordingly, in a first aspect, provided herein are affinity reagents having affinity for particular target molecules and comprising a unique DNA barcode, where the affinity reagent is useful to detect and measure the abundance of targets in a sample. Advantageously, a plurality of affinity reagents can be used to simultaneously measure a plurality of targets in a single sample. Accordingly, in some cases, affinity reagents of this disclosure are provided as a library of affinity reagents for multiplexed detection and measurement of multiple distinct targets in a single sample. As used herein, the term “affinity reagent” refers to an antibody, peptide, nucleic acid, or other small molecule that specifically binds to a biological molecule (“biomolecule”) of interest in order to identify, track, capture, and/or influence its activity. In some embodiments, the affinity reagent is an antibody. In other embodiments, the affinity reagent is an aptamer.


In some cases, the affinity reagents are antibodies having specificity for particular protein (e.g., antigen) targets, where the antibodies are linked to a DNA barcode. In such cases, an antibody affinity reagent is contacted to a sample under conditions that promote binding of the affinity reagent to its target antigen when present in said sample. Antibodies that are bound to their target antigens can be separated from unbound antibodies by washing unbound reagents from the sample. In some embodiments, the DNA bar code associated with the affinity reagent is amplified, such as by polymerase chain reaction (PCR), and the amplified barcode DNA is subjected to DNA sequencing to provide a measure of target antigen in the contacted sample.


Any antibody can be used for the affinity reagents of this disclosure. Preferably, the antibodies bind tightly (i.e., have high affinity for) target antigens. It will be understood that antibodies selected for use in affinity reagents will vary according to the particular application. In some cases, the antibodies have affinity for a particular protein only when in a certain conformation or having a specific modification.


In some embodiments, one or more modifications are made to the fragment crystallizable region (Fc region) of the affinity reagent antibody. The Fc region is the tail region of an antibody that interacts with cell surface receptors and some proteins of the complement system. In other embodiments, the modification is made to a common region far from the target binding region. In this manner, one may obtain a library of antibodies affinity reagents having specificity for desired targets, each antibody chemically modified to include a linked DNA barcode of known sequence. In certain embodiments, the DNA barcode sequence is flanked by common sequences.


In other embodiments, the affinity reagents are aptamers. Aptamers are peptides and nucleic acid molecules that bind specifically to various biological molecules and are useful for in vitro or in vivo localization and quantification of various biological molecules. Aptamers are useful in biotechnological and therapeutic applications as they offer molecular recognition properties that rival that of the commonly used biomolecule, antibodies. In addition to their discriminate recognition, aptamers offer advantages over antibodies as they can be engineered completely in a test tube, are readily produced by chemical synthesis, possess desirable storage properties, and elicit little or no immunogenicity in therapeutic applications. Generally, nucleic acid aptamers are nucleic acid species that have been engineered through repeated rounds of in vitro selection or equivalently, SELEX (systematic evolution of ligands by exponential enrichment) to bind to various molecular targets such as small molecules, proteins, nucleic acids, and even cells, tissues and organisms.


Peptide aptamers are peptides selected or engineered to bind specific target molecules. These proteins consist of one or more peptide loops of variable sequence displayed by a protein scaffold. They can be isolated from combinatorial libraries and, in some cases, modified by directed mutation or rounds of variable region mutagenesis and selection. In vivo, peptide aptamers can bind cellular protein targets and exert biological effects, including interference with the normal protein interactions of their targeted molecules with other proteins. Libraries of peptide aptamers have been used as “mutagens,” in studies in which an investigator introduces a library that expresses different peptide aptamers into a cell population, selects for a desired phenotype, and identifies those aptamers associated with that phenotype.


As demonstrated in the Example section herein, genes from multiple HPV strains were cloned and expressed in vitro to produce a library of HPV antigens. When DNA barcodes and their flanking sequences were linked to these antigens, the resulting affinity reagents could detect the presence of particular HPV strain DNA in patient samples.


Like antibody affinity reagents, aptamer affinity reagents comprise a linked DNA barcode sequence. In some cases, the linker is a cleavable protein photocrosslinker, which can be photo-cleaved from the antibody or aptamer. In other cases, the linker is a ligand comprising a DNA barcode which can append to a target with a fusion tag. For example, the linker may be a Halo ligand comprising a barcode sequence appended to a Halo fusion tag. In other cases, the linker comprises a fluorescent probe in addition to the DNA barcode.


Once the library of antibodies is assembled. Each antibody is chemically modified in step 140 to add a linker that includes a unique DNA barcode, which is an identifying sequence flanked at its 5′ and 3′ ends by a set of common sequences. In certain embodiments, the DNA barcode comprises a nucleotide sequence of GCTGTACGGATT (SEQ ID NO:1). Other DNA barcode sequences are set forth in Table 1. Exemplary linker sequences are set forth in Table 2. The common sequences act as a pair of amplifying sequences. In some embodiments, each barcode sequence (bold font) is flanked by a 5′ flanking sequence and a 3′ flanking sequence. In some cases, the 5′ flanking sequence is (CCACCGCTGAGCAATAACTA; SEQ ID NO:2). In some cases, the 3′ flanking sequence is (CGTAGATGAGTCAACGGCCT; SEQ ID NO:3).









TABLE 1







Exemplary Barcode Sequences













Barcode



Barcode name
barcode sequence
SEQ ID NO:







Halo_BC1

GTAGTGACAGGT

  4







Halo_BC2

TCTGTGAAGTCC

  5







Halo_BC3

ATCAGATCGCCT

  6







Halo_BC4

AATGTGGTCTCG

  7







Halo_BC5

CCTCTCCAAACA

  8







Halo_BC6

TACTGGACAAGG

  9







Halo_BC7

TATCGGAGTCCT

 10







Halo_BC8

GGTGGAGTTACT

 11







Halo_BC9

CGGCTACTATTG

 12







Halo_BC10

CCGAGCTATGTA

 13







Halo_BC11

ACTACGTCCAAC

 14







Halo_BC12

TTCATCCGAACG

 15







Halo_BC13

CGAAACGCTTAG

 16







Halo_BC14

GCCTAAGTTCCA

 17







Halo_BC15

CAATTCCCACGT

 18







Halo_BC16

CGGTGAGACATA

 19







Halo_BC17

CTCTGAGGTTTG

 20







Halo_BC18

TACTGTCACCCA

 21







Halo_BC19

CAGGAGGTACAT

 22







Halo_BC20

CTTCCTACAGCA

 23







Halo_BC21

TAGAAACCGAGG

 24







Halo_BC22

GAAAAGCGTACC

 25







Halo_BC23

CGCTCATAACTC

 26







Halo_BC24

GGCATATACGAC

 27







Halo_BC25

GTGCTCTATCAC

 28







Halo_BC26

GGAGCATTTCAC

 29







Halo_BC27

ATGGGTCTTCTG

 30







Halo_BC28

AAGTCCGTGAAC

 31







Halo_BC29

TGACATAGAGGG

 32







Halo_BC30

CGTCAATCGTGT

 33







Halo_BC31

GTTCGAAGCAAC

 34







Halo_BC32

ACCCGAATTCAC

 35







Halo_BC33

GAGGACTTCACA

 36







Halo_BC34

GATTCCACCGTA

 37







Halo_BC35

GTATTCGCCATG

 38







Halo_BC36

GCTTGTTATCCG

 39







Halo_BC37

CGTCCAACTATG

 40







Halo_BC38

GGTAACAGTGAC

 41







Halo_BC39

GCGCAAAAGAAG

 42







Halo_BC40

TGTGGTTGATCG

 43







Halo_BC41

TGTGGGATTGTG

 44







Halo_BC42

TGCTTCGGGATA

 45







Halo_BC43

GACAGCTCGTTA

 46







Halo_BC44

TAAGAAGCGCTC

 47







Halo_BC45

CATACACACTCC

 48







Halo_BC46

TGCCGCCAAAAT

 49







Halo_BC47

CGGACCTTCTAA

 50







Halo_BC48

TCTCACGTCAAC

 51







Halo_BC49

CGCAAGAGAACA

 52







Halo_BC50

TTAGCTTCCCTG

 53







Halo_BC51

GAAGCCAAGCAT

 54







Halo_BC52

TTCGTAGCGTGT

 55







Halo_BC53

GTCGCTGATCAA

 56







Halo_BC54

TCAACTGATCGG

 57







Halo_BC55

CCAGTTTCTACG

 58







Halo_BC56

ACCCATTGCGAT

 59







Halo_BC57

TCACCACCCTAT

 60







Halo_BC58

GGTCTTCACTTC

 61







Halo_BC59

GTTAGAGATGGG

 62







Halo_BC60

TCTTGCACACTC

 63







Halo_BC61

TTTTCTCTGCGG

 64







Halo_BC62

TCAGCCGAGTTA

 65







Halo_BC63

CTCGTGATCAGA

 66







Halo_BC64

CCTTTCTCGGAA

 67







Halo_BC65

ACGCTAGAGCTT

 68







Halo_BC66

TTCCCCGTTTAG

 69







Halo_BC67

AGAATCGCAACC

 70







Halo_BC68

GGAAGGAACTGT

 71







Halo_BC69

CTTGGCATCTTC

 72







Halo_BC70

AGGCCGATTTGT

 73







Halo_BC71

AACAAAGGGTCC

 74







Halo_BC72

CAATTGGTAGCC

 75







Halo_BC73

ACCATCGACTCA

 76







Halo_BC74

CGTGAGATGAAC

 77







Halo_BC75

CCATGGTCTTGT

 78







Halo_BC76

CAGATATGAGCGC

 79







Halo_BC77

GTGTGACAGAGT

 80







Halo_BC78

ATTGTGTGACGG

 81







Halo_BC79

CGGTAGTTTGCT

 82







Halo_BC80

GGACATGTCCAT

 83







Halo_BC81

TTGAGGGAGACA

 84







Halo_BC82

CGACATCCTCTA

 85







Halo_BC83

TGAGCGAGTTCA

 86







Halo_BC84

GACCTTCGGATT

 87







Halo_BC85

TGTAGATCCGCA

 88







Halo_BC86

TGGCACTCTAGA

 89







Halo_BC87

AACAGTAGTCGG

 90







Halo_BC88

TCATGCGGAAAG

 91







Halo_BC89

TCGAATCGTGTC

 92







Halo_BC90

GGTGTATAGCCA

 93







Halo_BC91

TTGCAGTGCAAG

 94







Halo_BC92

CGATTGCAGAAG

 95







Halo_BC93

CCAGACGTTGTT

 96







Halo_BC94

TGGTGGCCATAA

 97







Halo_BC95

CAGAGTCAATGG

 98







Halo_BC96

CCTATCATTCCC

 99







Halo_BC97

GAGGTATGACTC

100







Halo_BC98

CTAGGTCAAGTC

101







Halo_BC99

ACTCGGCTTTCA

102







Halo_BC100

TTCACAAGCGGA

103

















TABLE 2







Exemplary Linker Sequences









Name of




barcode
Linker:
SEQ


included
flanking seq - barcode sequence -
ID


in linker
flanking seq
NO:





Halo_BC1
CCACCGCTGAGCAATAACTA GTAGTGACAGGT
104



CGTAGATGAGTCAACGGCCT






Halo_BC2
CCACCGCTGAGCAATAACTA TCTGTGAAGTCC
105



CGTAGATGAGTCAACGGCCT






Halo_BC3
CCACCGCTGAGCAATAACTA ATCAGATCGCCT
106



CGTAGATGAGTCAACGGCCT






Halo_BC4
CCACCGCTGAGCAATAACTA AATGTGGTCTCG
107



CGTAGATGAGTCAACGGCCT






Halo_BC5
CCACCGCTGAGCAATAACTA CCTCTCCAAACA
108



CGTAGATGAGTCAACGGCCT






Halo_BC6
CCACCGCTGAGCAATAACTA TACTGGACAAGG
109



CGTAGATGAGTCAACGGCCT






Halo_BC7
CCACCGCTGAGCAATAACTA TATCGGAGTCCT
110



CGTAGATGAGTCAACGGCCT






Halo_BC8
CCACCGCTGAGCAATAACTA GGTGGAGTTACT
111



CGTAGATGAGTCAACGGCCT






Halo_BC9
CCACCGCTGAGCAATAACTA CGGCTACTATTG
112



CGTAGATGAGTCAACGGCCT






Halo_BC10
CCACCGCTGAGCAATAACTA CCGAGCTATGTA
113



CGTAGATGAGTCAACGGCCT






Halo_BC11
CCACCGCTGAGCAATAACTA ACTACGTCCAAC
114



CGTAGATGAGTCAACGGCCT






Halo_BC12
CCACCGCTGAGCAATAACTA TTCATCCGAACG
115



CGTAGATGAGTCAACGGCCT






Halo_BC13
CCACCGCTGAGCAATAACTA CGAAACGCTTAG
116



CGTAGATGAGTCAACGGCCT






Halo_BC14
CCACCGCTGAGCAATAACTA GCCTAAGTTCCA
117



CGTAGATGAGTCAACGGCCT






Halo_BC15
CCACCGCTGAGCAATAACTA CAATTCCCACGT
118



CGTAGATGAGTCAACGGCCT






Halo_BC16
CCACCGCTGAGCAATAACTA CGGTGAGACATA
119



CGTAGATGAGTCAACGGCCT






Halo_BC17
CCACCGCTGAGCAATAACTA CTCTGAGGTTTG
120



CGTAGATGAGTCAACGGCCT






Halo_BC18
CCACCGCTGAGCAATAACTA TACTGTCACCCA
121



CGTAGATGAGTCAACGGCCT






Halo_BC19
CCACCGCTGAGCAATAACTA CAGGAGGTACAT
122



CGTAGATGAGTCAACGGCCT






Halo_BC20
CCACCGCTGAGCAATAACTA CTTCCTACAGCA
123



CGTAGATGAGTCAACGGCCT






Halo_BC21
CCACCGCTGAGCAATAACTA TAGAAACCGAGG
124



CGTAGATGAGTCAACGGCCT






Halo_BC22
CCACCGCTGAGCAATAACTA GAAAAGCGTACC
125



CGTAGATGAGTCAACGGCCT






Halo_BC23
CCACCGCTGAGCAATAACTA CGCTCATAACTC
126



CGTAGATGAGTCAACGGCCT






Halo_BC24
CCACCGCTGAGCAATAACTA GGCATATACGAC
127



CGTAGATGAGTCAACGGCCT






Halo_BC25
CCACCGCTGAGCAATAACTA GTGCTCTATCAC
128



CGTAGATGAGTCAACGGCCT






Halo_BC26
CCACCGCTGAGCAATAACTA GGAGCATTTCAC
129



CGTAGATGAGTCAACGGCCT






Halo_BC27
CCACCGCTGAGCAATAACTA ATGGGTCTTCTG
130



CGTAGATGAGTCAACGGCCT






Halo_BC28
CCACCGCTGAGCAATAACTA AAGTCCGTGAAC
131



CGTAGATGAGTCAACGGCCT






Halo_BC29
CCACCGCTGAGCAATAACTA TGACATAGAGGG
132



CGTAGATGAGTCAACGGCCT






Halo_BC30
CCACCGCTGAGCAATAACTA CGTCAATCGTGT
133



CGTAGATGAGTCAACGGCCT






Halo_BC31
CCACCGCTGAGCAATAACTA GTTCGAAGCAAC
134



CGTAGATGAGTCAACGGCCT






Halo_BC32
CCACCGCTGAGCAATAACTA ACCCGAATTCAC
135



CGTAGATGAGTCAACGGCCT






Halo_BC33
CCACCGCTGAGCAATAACTA GAGGACTTCACA
136



CGTAGATGAGTCAACGGCCT






Halo_BC34
CCACCGCTGAGCAATAACTA GATTCCACCGTA
137



CGTAGATGAGTCAACGGCCT






Halo_BC35
CCACCGCTGAGCAATAACTA GTATTCGCCATG
138



CGTAGATGAGTCAACGGCCT






Halo_BC36
CCACCGCTGAGCAATAACTA GCTTGTTATCCG
139



CGTAGATGAGTCAACGGCCT






Halo_BC37
CCACCGCTGAGCAATAACTA CGTCCAACTATG
140



CGTAGATGAGTCAACGGCCT






Halo_BC38
CCACCGCTGAGCAATAACTA GGTAACAGTGAC
141



CGTAGATGAGTCAACGGCCT






Halo_BC39
CCACCGCTGAGCAATAACTA GCGCAAAAGAAG
142



CGTAGATGAGTCAACGGCCT






Halo_BC40
CCACCGCTGAGCAATAACTA TGTGGTTGATCG
143



CGTAGATGAGTCAACGGCCT






Halo_BC41
CCACCGCTGAGCAATAACTA TGTGGGATTGTG
144



CGTAGATGAGTCAACGGCCT






Halo_BC42
CCACCGCTGAGCAATAACTA TGCTTCGGGATA
145



CGTAGATGAGTCAACGGCCT






Halo_BC43
CCACCGCTGAGCAATAACTA GACAGCTCGTTA
146



CGTAGATGAGTCAACGGCCT






Halo_BC44
CCACCGCTGAGCAATAACTA TAAGAAGCGCTC
147



CGTAGATGAGTCAACGGCCT






Halo_BC45
CCACCGCTGAGCAATAACTA CATACACACTCC
148



CGTAGATGAGTCAACGGCCT






Halo_BC46
CCACCGCTGAGCAATAACTA TGCCGCCAAAAT
149



CGTAGATGAGTCAACGGCCT






Halo_BC47
CCACCGCTGAGCAATAACTA CGGACCTTCTAA
150



CGTAGATGAGTCAACGGCCT






Halo_BC48
CCACCGCTGAGCAATAACTA TCTCACGTCAAC
151



CGTAGATGAGTCAACGGCCT






Halo_BC49
CCACCGCTGAGCAATAACTA CGCAAGAGAACA
152



CGTAGATGAGTCAACGGCCT






Halo_BC50
CCACCGCTGAGCAATAACTA TTAGCTTCCCTG
153



CGTAGATGAGTCAACGGCCT






Halo_BC51
CCACCGCTGAGCAATAACTA GAAGCCAAGCAT
154



CGTAGATGAGTCAACGGCCT






Halo_BC52
CCACCGCTGAGCAATAACTA TTCGTAGCGTGT
155



CGTAGATGAGTCAACGGCCT






Halo_BC53
CCACCGCTGAGCAATAACTA GTCGCTGATCAA
156



CGTAGATGAGTCAACGGCCT






Halo_BC54
CCACCGCTGAGCAATAACTA TCAACTGATCGG
157



CGTAGATGAGTCAACGGCCT






Halo_BC55
CCACCGCTGAGCAATAACTA CCAGTTTCTACG
158



CGTAGATGAGTCAACGGCCT






Halo_BC56
CCACCGCTGAGCAATAACTA ACCCATTGCGAT
159



CGTAGATGAGTCAACGGCCT






Halo_BC57
CCACCGCTGAGCAATAACTA TCACCACCCTAT
160



CGTAGATGAGTCAACGGCCT






Halo_BC58
CCACCGCTGAGCAATAACTA GGTCTTCACTTC
161



CGTAGATGAGTCAACGGCCT






Halo_BC59
CCACCGCTGAGCAATAACTA GTTAGAGATGGG
162



CGTAGATGAGTCAACGGCCT






Halo_BC60
CCACCGCTGAGCAATAACTA TCTTGCACACTC
163



CGTAGATGAGTCAACGGCCT






Halo_BC61
CCACCGCTGAGCAATAACTA TTTTCTCTGCGG
164



CGTAGATGAGTCAACGGCCT






Halo_BC62
CCACCGCTGAGCAATAACTA TCAGCCGAGTTA
165



CGTAGATGAGTCAACGGCCT






Halo_BC63
CCACCGCTGAGCAATAACTA CTCGTGATCAGA
166



CGTAGATGAGTCAACGGCCT






Halo_BC64
CCACCGCTGAGCAATAACTA CCTTTCTCGGAA
167



CGTAGATGAGTCAACGGCCT






Halo_BC65
CCACCGCTGAGCAATAACTA ACGCTAGAGCTT
168



CGTAGATGAGTCAACGGCCT






Halo_BC66
CCACCGCTGAGCAATAACTA TTCCCCGTTTAG
169



CGTAGATGAGTCAACGGCCT






Halo_BC67
CCACCGCTGAGCAATAACTA AGAATCGCAACC
170



CGTAGATGAGTCAACGGCCT






Halo_BC68
CCACCGCTGAGCAATAACTA GGAAGGAACTGT
171



CGTAGATGAGTCAACGGCCT






Halo_BC69
CCACCGCTGAGCAATAACTA CTTGGCATCTTC
172



CGTAGATGAGTCAACGGCCT






Halo_BC70
CCACCGCTGAGCAATAACTA AGGCCGATTTGT
173



CGTAGATGAGTCAACGGCCT






Halo_BC71
CCACCGCTGAGCAATAACTA AACAAAGGGTCC
174



CGTAGATGAGTCAACGGCCT






Halo_BC72
CCACCGCTGAGCAATAACTA CAATTGGTAGCC
175



CGTAGATGAGTCAACGGCCT






Halo_BC73
CCACCGCTGAGCAATAACTA ACCATCGACTCA
176



CGTAGATGAGTCAACGGCCT






Halo_BC74
CCACCGCTGAGCAATAACTA CGTGAGATGAAC
177



CGTAGATGAGTCAACGGCCT






Halo_BC75
CCACCGCTGAGCAATAACTA CCATGGTCTTGT
178



CGTAGATGAGTCAACGGCCT






Halo_BC76
CCACCGCTGAGCAATAACTA AGATATGAGCGC
179



CGTAGATGAGTCAACGGCCT






Halo_BC77
CCACCGCTGAGCAATAACTA GTGTGACAGAGT
180



CGTAGATGAGTCAACGGCCT






Halo_BC78
CCACCGCTGAGCAATAACTA ATTGTGTGACGG
181



CGTAGATGAGTCAACGGCCT






Halo_BC79
CCACCGCTGAGCAATAACTA CGGTAGTTTGCT
182



CGTAGATGAGTCAACGGCCT






Halo_BC80
CCACCGCTGAGCAATAACTA GGACATGTCCAT
183



CGTAGATGAGTCAACGGCCT






Halo_BC81
CCACCGCTGAGCAATAACTA TTGAGGGAGACA
184



CGTAGATGAGTCAACGGCCT






Halo_BC82
CCACCGCTGAGCAATAACTA CGACATCCTCTA
185



CGTAGATGAGTCAACGGCCT






Halo_BC83
CCACCGCTGAGCAATAACTA TGAGCGAGTTCA
186



CGTAGATGAGTCAACGGCCT






Halo_BC84
CCACCGCTGAGCAATAACTA GACCTTCGGATT
187



CGTAGATGAGTCAACGGCCT






Halo_BC85
CCACCGCTGAGCAATAACTA TGTAGATCCGCA
188



CGTAGATGAGTCAACGGCCT






Halo_BC86
CCACCGCTGAGCAATAACTA TGGCACTCTAGA
189



CGTAGATGAGTCAACGGCCT






Halo_BC87
CCACCGCTGAGCAATAACTA AACAGTAGTCGG
190



CGTAGATGAGTCAACGGCCT






Halo_BC88
CCACCGCTGAGCAATAACTA TCATGCGGAAAG
191



CGTAGATGAGTCAACGGCCT






Halo_BC89
CCACCGCTGAGCAATAACTA TCGAATCGTGTC
192



CGTAGATGAGTCAACGGCCT






Halo_BC90
CCACCGCTGAGCAATAACTA GGTGTATAGCCA
193



CGTAGATGAGTCAACGGCCT






Halo_BC91
CCACCGCTGAGCAATAACTA TTGCAGTGCAAG
194



CGTAGATGAGTCAACGGCCT






Halo_BC92
CCACCGCTGAGCAATAACTA CGATTGCAGAAG
195



CGTAGATGAGTCAACGGCCT






Halo_BC93
CCACCGCTGAGCAATAACTA CCAGACGTTGTT
196



CGTAGATGAGTCAACGGCCT






Halo_BC94
CCACCGCTGAGCAATAACTA TGGTGGCCATAA
197



CGTAGATGAGTCAACGGCCT






Halo_BC95
CCACCGCTGAGCAATAACTA CAGAGTCAATGG
198



CGTAGATGAGTCAACGGCCT






Halo_BC96
CCACCGCTGAGCAATAACTA CCTATCATTCCC
199



CGTAGATGAGTCAACGGCCT






Halo_BC97
CCACCGCTGAGCAATAACTA GAGGTATGACTC
200



CGTAGATGAGTCAACGGCCT






Halo_BC98
CCACCGCTGAGCAATAACTA CTAGGTCAAGTC
201



CGTAGATGAGTCAACGGCCT






Halo_BC99
CCACCGCTGAGCAATAACTA ACTCGGCTTTCA
202



CGTAGATGAGTCAACGGCCT






Halo_BC100
CCACCGCTGAGCAATAACTA TTCACAAGCGGA
203



CGTAGATGAGTCAACGGCCT









Methods

In another aspect, provided herein are methods for multiplexed detection and measurement of multiple targets in a sample using affinity reagents that comprise a unique DNA barcode. In some cases, the method comprises contacting affinity reagents comprising unique DNA barcodes to a sample under conditions that promote binding of the affinity reagents to target antigens when present in said sample. The methods provided herein can employ a variety of affinity reagents, including those favored by a user, in a multiplexed set to measure the abundance of their respective targets in a sample. The methods provided herein permit measurement of the levels of proteins or any detectable antigens in high throughput. This method uses available antibodies which enables the user to use those antibodies that have the best specification for purpose. This does not require the user to remain within a closed system such as a proprietary set of aptamers or a set of reagents for which binding data are not public. The method will have a wide dynamic range and can be multiplexed in the thousands.


In cases in which the affinity reagents are antibodies and the targets are antigens, antibodies that are bound to their target antigens can be separated from unbound antibodies. Any method of uniquely detecting and measuring the DNA barcodes can be used. In some embodiments, the DNA barcode associated with the affinity reagent is amplified, such as by polymerase chain reaction (PCR) or another amplification technique, and the amplified barcode DNA is subjected to DNA sequencing to provide a measure of target protein in the contacted sample. In other cases, the DNA barcode is detected using, for example, a nucleic acid array or aptamers.


Referring to the flow chart of FIG. 1, the methods in some cases comprise obtaining a biological sample (see step 110). In step 120, the user may define a list of target proteins (or other targets) to be detected and quantified in the sample. In step 130, affinity reagents that specifically recognize each of the targets on the list are prepared by linking a unique barcode to antibodies or aptamers having affinity for those targets.


In some embodiments, protein measurement comprises separating bound antibodies from unbound antibodies. In some cases, the sample is brought into contact with the antibody mix under conditions that promote binding of affinity reagents to their targets if presented in the sample. Unbound antibodies are washed away in step 160.


Any appropriate method can be used to detect and measure binding of affinity reagents to their targets in the sample. For example, referring to step 170 of FIG. 1, PCR-based amplification can be performed directly on the sample using primers that correspond to the sequences that flank the bar code. As described above, the flanking amplifying sequences can comprise nucleotide sequences of CCACCGCTGAGCAATAACTA (SEQ ID NO:2) and CGTAGATGAGTCAACGGCCT (SEQ ID NO:3). By sequencing the resulting amplified DNA, the number of each type of target can be assessed based on the barcode. In other embodiments, linkers containing the barcodes are released from the samples by photo cleavage or a chemical cleavage, and then collected and used to run a PCR reaction as above. The resulting amplified DNA is subjected to DNA sequencing to assess the number of each type of target based on the barcode. In yet other embodiments, the linkers containing both the barcodes and fluorescent tag are released from the samples by photo cleavage, and then collected. They are then used to hybridize to a DNA microarray that specifically recognizes the barcodes.


The terms “quantity”, “amount” and “level” are synonymous and generally well-understood in the art. The terms as used herein may particularly refer to an absolute quantification of a target molecule in a sample, or to a relative quantification of a target molecule in a sample, i.e., relative to another value such as relative to a reference value or to a range of values indicating a base-line expression of the biomarker. These values or ranges can be obtained from a single subject (e.g., human patient) or aggregated from a group of subjects. In some cases, target measurements are compared to a standard or set of standards.


In a further aspect, provided herein are methods for detecting and quantifying a subject's immune response to a disease (e.g., cancer, autoimmune disorder) or infectious agent such as a pathogenic microorganism. In such cases, affinity reagents are selected for their affinity for molecular targets associated with a particular disease or infectious agent. Advantageously, the affinity reagents described herein are well suited for multiplexed screening of a sample for many different infections. For example, one may assay a sample for many infections simultaneously to see which induced an immune response and to which infection-associated proteins triggered the response. Samples appropriate for use according to the methods provided herein include biological samples such as, for example, blood, plasma, serum, urine, saliva, tissues, cells, organs, organisms or portions thereof (e.g., mosquitoes, bacteria, plants or plant material), patient samples (e.g., feces or body fluids, such as urine, blood, serum, plasma, or cerebrospinal fluid), food samples, drinking water, and agricultural products.


In certain embodiments, affinity reagents described herein are used to detect and, in some cases, monitor a subject's immune response to an infectious pathogen. By way of example, pathogens may comprise viruses including, without limitation, flaviruses, human immunodeficiency virus (HIV), Ebola virus, single stranded RNA viruses, single stranded DNA viruses, double-stranded RNA viruses, double-stranded DNA viruses. Other pathogens include but are not limited to parasites (e.g., malaria parasites and other protozoan and metazoan pathogens (plasmodia species, leishmania species, schistosoma species, trypanosoma species)), bacteria (e.g., Mycobacteria, in particular, M. tuberculosis, Salmonella, Streptococci, E. coli, Staphylococci), fungi (e.g., candida species, aspergillus species, Pneumocystis jiroveciiand other Pneumocystis species), and prions. In some cases, the pathogenic microorganism, e.g. pathogenic bacteria, may be one which causes cancer in certain human cell types.


In certain embodiments, the methods detect viruses including, without limitation, the human-pathogenic viruses such Zika virus (e.g., Zika strain from the Americas, ZIKV), yellow fever virus, and dengue virus serotypes 1 (DENV1) and 3 (DENV3), and closely related viruses such as the chikungunya virus (CHIKV).


The terms “detect” or “detection” as used herein indicate the determination of the existence, presence or fact of a target molecule in a limited portion of space, including but not limited to a sample, a reaction mixture, a molecular complex and a substrate including a platform and an array. Detection is “quantitative” when it refers, relates to, or involves the measurement of quantity or amount of the target or signal (also referred as quantitation), which includes but is not limited to any analysis designed to determine the amounts or proportions of the target or signal. Detection is “qualitative” when it refers, relates to, or involves identification of a quality or kind of the target or signal in terms of relative abundance to another target or signal, which is not quantified.


The terms “nucleic acid” and “nucleic acid molecule,” as used herein, refer to a compound comprising a nucleobase and an acidic moiety, e.g., a nucleoside, a nucleotide, or a polymer of nucleotides. Typically, polymeric nucleic acids, e.g., nucleic acid molecules comprising three or more nucleotides are linear molecules, in which adjacent nucleotides are linked to each other via a phosphodiester linkage. In some embodiments, “nucleic acid” refers to individual nucleic acid residues (e.g. nucleotides and/or nucleosides). In some embodiments, “nucleic acid” refers to an oligonucleotide chain comprising three or more individual nucleotide residues. As used herein, the terms “oligonucleotide” and “polynucleotide” can be used interchangeably to refer to a polymer of nucleotides (e.g., a string of at least three nucleotides). In some embodiments, “nucleic acid” encompasses RNA as well as single and/or double-stranded DNA. Nucleic acids may be naturally occurring, for example, in the context of a genome, a transcript, an mRNA, tRNA, rRNA, siRNA, snRNA, a plasmid, cosmid, chromosome, chromatid, or other naturally occurring nucleic acid molecule. On the other hand, a nucleic acid molecule may be a non-naturally occurring molecule, e.g., a recombinant DNA or RNA, an artificial chromosome, an engineered genome, or fragment thereof, or a synthetic DNA, RNA, DNA/RNA hybrid, or include non-naturally occurring nucleotides or nucleosides. Furthermore, the terms “nucleic acid,” “DNA,” “RNA,” and/or similar terms include nucleic acid analogs, i.e. analogs having other than a phosphodiester backbone. Nucleic acids can be purified from natural sources, produced using recombinant expression systems and optionally purified, chemically synthesized, etc. Where appropriate, e.g., in the case of chemically synthesized molecules, nucleic acids can comprise nucleoside analogs such as analogs having chemically modified bases or sugars, and backbone modifications. A nucleic acid sequence is presented in the 5′ to 3′ direction unless otherwise indicated. In some embodiments, a nucleic acid is or comprises natural nucleosides (e.g. adenosine, thymidine, guanosine, cytidine, uridine, deoxyadenosine, deoxythymidine, deoxyguanosine, and deoxycytidine); nucleoside analogs (e.g., 2-aminoadenosine, 2-thiothymidine, inosine, pyrrolo-pyrimidine, 3-methyl adenosine, 5-methylcytidine, 2-aminoadenosine, C5-bromouridine, C5-fluorouridine, C5-iodouridine, C5-propynyl-uridine, C5-propynyl-cytidine, C5-methylcytidine, 2-aminoadeno sine, 7-deazaadenosine, 7-deazaguanosine, 8-oxoadenosine, 8-oxoguanosine, O(6)-methylguanine, and 2-thiocytidine); chemically modified bases; biologically modified bases (e.g., methylated bases); intercalated bases; modified sugars (e.g., 2′-fluororibose, ribose, 2′-deoxyribose, arabinose, and hexose); and/or modified phosphate groups (e.g., phosphorothioates and 5′-N-phosphoramidite linkages).


The terms “protein,” “peptide,” and “polypeptide” are used interchangeably herein and refer to a polymer of amino acid residues linked together by peptide (amide) bonds. The terms refer to a protein, peptide, or polypeptide of any size, structure, or function. Typically, a protein, peptide, or polypeptide will be at least three amino acids long. A protein, peptide, or polypeptide may refer to an individual protein or a collection of proteins. One or more of the amino acids in a protein, peptide, or polypeptide may be modified, for example, by the addition of a chemical entity such as a carbohydrate group, a hydroxyl group, a phosphate group, a farnesyl group, an isofarnesyl group, a fatty acid group, a linker for conjugation, functionalization, or other modification, etc. A protein, peptide, or polypeptide may also be a single molecule or may be a multi-molecular complex. A protein, peptide, or polypeptide may be just a fragment of a naturally occurring protein or peptide. A protein, peptide, or polypeptide may be naturally occurring, recombinant, or synthetic, or any combination thereof. A protein may comprise different domains, for example, a nucleic acid binding domain and a nucleic acid cleavage domain. In some embodiments, a protein comprises a proteinaceous part, e.g., an amino acid sequence constituting a nucleic acid binding domain, and an organic compound, e.g., a compound that can act as a nucleic acid cleavage agent.


Articles of Manufacture

In another aspect, provided herein are articles of manufacture useful for detecting target molecules, including infection-associated or disease-associated molecules (e.g., cancer associated). In certain embodiments, the article of manufacture is a kit for detecting an immune response to a pathogen, where the kit comprises a plurality of affinity reagents, each of which comprises a linked DNA barcode, and one or more of reagents to amplify DNA barcodes using polymerase chain reaction. Preferably, the linked DNA barcode is flanked by a pair of amplifying nucleotide sequences, and each affinity reagent has a different identifying barcode sequence from other affinity reagents. Optionally, a kit can further include instructions for performing the detection and/or amplification methods described herein.


Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.


The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”


Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.


Unless otherwise indicated, any nucleic acid sequences are written left to right in 5′ to 3′ orientation; amino acid sequences are written left to right in amino to carboxy orientation, respectively.


Schematic flow charts included are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.


The present invention is further illustrated by the following Examples, which in no way should be construed as further limiting. The entire contents of all of the references (including literature references, issued patents, published patent applications, and co-pending patent applications) cited throughout this application are hereby expressly incorporated herein by reference.


EXAMPLE

To develop a quantitative, multiplexed, bar-coded antigen library for detection of immune responses in pathogen induced cancers, we cloned 97 HPV genes from the HPV strains 6, 16, 18, 31, 33, 35, 39, 45, 51, 52, and 58 into the pJFT7-3XFLAG-Halo vector. This vector includes two fusion tags 3XFLAG and Halo fusion. As shown in FIG. 2, the HPV proteome was expressed in a cell-free human IVT system with a 97% success rate. Except for the HPV11 E5a and HPV 31 E5 antigens, full-length proteins for the HPV proteome were successfully expressed.


Unique DNA barcodes (attached to Halo ligand) were appended to 20 antigens from HPV strains 16, 18 (high risk HPV strains) and 6 (a low risk HPV strain). After capturing the expressed and barcoded HPV antigens with FLAG magnetic beads we combined all the HPV antigens into a single protein cocktail. This barcoded protein cocktail was then probed against 10 HPV infected OPC patient samples and 10 control samples. After capturing in protein, A/G magnetic beads we amplified the barcodes and ran the samples on NextSeq after multiplexing. From our sequencing run we obtained 450K reads per sample with 71% mapping ratio to our barcodes. The normalized percentage of each barcode showed distinct enrichment of certain HPV antigens in the OPC patient samples (FIG. 3). In contrast, most of the control samples showed only less than 10% barcode enrichment for the HPV antigens. This clearly demonstrates that the barcoded HPV proteome can be utilized to quantify the immune responses for certain HPV antigens in OPC patient sera. We observed a heterogeneous immune response for the HPV positive OPC serum sample, where antibodies were detected for E1, E2, E6 and E7 HPV 16 antigens. We also detected similar patterns for antibody profiles when we amplified our unique barcodes with barcode specific PCR primers (FIG. 4).

Claims
  • 1. A composition comprising a plurality of modified affinity reagents, wherein each affinity reagent of the plurality comprises a linker, the linker comprising a unique identifying nucleotide sequence relative to other affinity reagents of the plurality flanked by a first amplifying nucleotide sequence and a second amplifying nucleotide sequence, wherein: (a) the first and second amplifying nucleotide sequence are independently selected from SEQ ID NOs: 2 or 3; or(b) the linker comprises one of SEQ ID NOs. 105-203.
  • 2. The composition of claim 1, wherein affinity reagents of the plurality are antibodies, peptide aptamers, or nucleic acid aptamers.
  • 3. The composition of claim 1, wherein the linker further comprises a cleavable protein photocrosslinker or a fluorescent moiety.
  • 4. The composition of claim 1, wherein the wherein the identifying nucleotide sequence has a length of about 10 nucleotides to about 20 nucleotides.
  • 5. The composition of claim 1, the wherein the identifying nucleotide sequence has a length of about 12 nucleotides.
  • 6. The composition of claim 1, wherein the identifying nucleotide sequence comprises about 50% of AT base pairs and about 50% of GC base pairs.
  • 7. A method for high throughput target molecule identification and quantification, comprising: contacting a sample with a plurality of modified affinity reagents under conditions that promote binding of modified affinity reagents of the plurality to target molecules if present in the contacted sample, wherein each modified affinity reagent of the plurality is coupled to a linker comprising an identifying nucleotide sequence flanked on each end by an amplifying nucleotide sequence, wherein (a) the amplifying nucleotide sequence comprises SEQ ID NO: 2 or 3 or (b) the linker comprises one of SEQ ID NOs: 105-203;removing unbound modified affinity reagent from the contacted sample; andamplifying and sequencing the identifying nucleotide sequence coupled to each bound modified affinity reagent whereby the target molecules are identified and quantified based on detection of identifying nucleotide sequences of the bound modified affinity reagents.
  • 8. The method of claim 7, wherein the affinity reagent is an antibody or an aptamer.
  • 9. The method of claim 8, wherein the affinity reagent is an antibody and wherein the linker is coupled to a region of the antibody that is not an antigen binding region.
  • 10. The method of claim 8, wherein the affinity reagent is an antibody and wherein the linker is coupled to a fragment crystallizable region (Fc region) of the antibody.
  • 11. The method of claim 7, wherein the identifying nucleotide sequence has a length of about 10 nucleotides to about 20 nucleotides.
  • 12. The method of claim 7, wherein the identifying nucleotide sequence has a length of about 12 nucleotides.
  • 13. The method of claim 7, wherein the identifying nucleotide sequence comprises about 50% of AT base pairs and about 50% of GC base pairs.
  • 14. The method of claim 7, wherein the amplifying sequence has a length ranging from 20 to 30 base pairs.
  • 15. The method of claim 7, wherein the linker further comprises a fluorescent protein or a cleavable protein photocrosslinker.
  • 16. A kit for high throughput protein quantification, comprising the composition comprising a plurality of modified affinity reagents of claim 1, the plurality comprising X modified affinity reagent(s), wherein: X is equal to or greater than 1.
CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 16/811,573, filed Mar. 6, 2020, which is a continuation of U.S. patent application Ser. No. 16/480,601, filed Jul. 24, 2019, which represents the national stage entry of PCT International Application No. PCT/US2018/018908, filed on Feb. 21, 2018, and claims the benefit of U.S. Application Ser. No. 62/461,681, filed on Feb. 21, 2017, each of which is incorporated by reference herein as if set forth in its entirety.

Provisional Applications (1)
Number Date Country
62461681 Feb 2017 US
Continuations (2)
Number Date Country
Parent 16811573 Mar 2020 US
Child 18675970 US
Parent 16480601 Jul 2019 US
Child 16811573 US