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Crosslinker-Modified Oligonucleotides

Custom DNA and RNA oligos functionalized with reactive crosslinker handles for controlled conjugation to proteins, antibodies, peptides, nanoparticles, polymers and assay surfaces.

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Overview Functional Group Map Crosslinker Classes Representative Crosslinkers Applications Reading FAQ Contact
Overview

Reactive Crosslinker Handles for Downstream Oligo Conjugation

Bio-Synthesis provides crosslinker-modified oligonucleotides for programs that require controlled covalent attachment between DNA/RNA oligos and proteins, antibodies, peptides, polymers, nanoparticles, assay surfaces or other biomolecules.

These constructs serve as defined bioconjugation intermediates. Depending on the partner molecule and workflow, Bio-Synthesis can configure oligos with amine-reactive, thiol-reactive, carboxyl-to-amine, aldehyde-reactive, heterobifunctional, homobifunctional or photoreactive crosslinker chemistry.

Common formats include SMCC-modified oligonucleotides, maleimide-functional oligos, NHS-activated oligos, hydrazide or aminooxy oligos, and photo-crosslinkable DNA/RNA probes used in antibody conjugation, nanoparticle assembly, surface immobilization and advanced nucleic-acid-based detection platforms.

NHS / Maleimide / SMCC Protein & Antibody Coupling Surface Immobilization Photoaffinity Handles HPLC / MS QC

Match the crosslinker to the partner molecule

Amine-bearing partners

NHS, Sulfo-NHS, TFP/STP or EDC/NHS systems for proteins, peptides, beads and surfaces.

Thiol-bearing partners

Maleimide, haloacetyl, pyridyldithiol or SMCC-style amine-to-thiol coupling.

Carbonyl/aldehyde partners

Hydrazide and aminooxy oligos for hydrazone or oxime-style conjugation.

Proximity capture

Diazirine, aryl azide, benzophenone or related photoreactive crosslinkers.

Oligonucleotide

Crosslinker Handle

Target Partner

The crosslinker architecture is selected around the oligo position, partner functional group, spacer length, reaction environment and downstream purification/QC plan.

Reactive Functional Group Map

Crosslinker Chemistry Selection Map

A practical summary of crosslinker classes, representative handles, conjugation targets, downstream constructs and primary design concerns.

Functional Group Compatibility

Choose the crosslinker based on both the oligonucleotide installation site and the available functional group on the conjugation partner.

Crosslinker Class Representative Handles / Reagents Targets on Partner Typical Downstream Constructs Main Design Concern
Homobifunctional DSS, BS3, DSP, DTSSP, EGS, BS(PEG)n Amine-bearing proteins, surfaces or assemblies Immobilized probes, multicomponent assay builds, networked capture systems Spacer length and over-crosslinking risk
Heterobifunctional SMCC, Sulfo-SMCC, EMCS, MBS, BMPH, BMPS, SPDP Amine plus thiol or disulfide-exchange partners Antibody-oligo conjugates, peptide-oligo conjugates, nanoparticle coupling Reaction sequence and chemoselectivity
Amine-Reactive NHS ester, Sulfo-NHS ester, TFP ester formats Lysines, terminal amines, amino-functional surfaces Protein labeling, carrier conjugation, bead or slide attachment Hydrolysis and aqueous stability
Sulfhydryl-Reactive Maleimide, iodoacetyl, bromoacetyl, pyridyldithiol Cysteine-containing proteins, peptides, engineered thiols Site-directed protein-DNA builds, reducible capture systems Free thiol availability and thioether stability
Carboxyl-to-Amine EDC, NHS, Sulfo-NHS activation schemes Carboxylated materials, proteins, polymers or particles Surface immobilization, hydrogel coupling, material functionalization Substrate pH tolerance and activation efficiency
Aldehyde-Reactive Hydrazide, aminooxy, oxime-forming handles Oxidized glycans or aldehyde-bearing biomaterials Glycoprotein-oligo conjugates, carbonyl-directed labeling Carbonyl generation and reaction kinetics
Photoreactive Sulfo-SANPAH, SDA, Sulfo-SDA, LC-SDA, SDAD, aryl azide, diazirine Nearby biomolecules under UV activation Photoaffinity probes, interaction capture, proximity labeling Light dose, nonspecific capture and probe positioning
Crosslinker Classes

Crosslinker Classes & Representative Items

Each class has a different conjugation logic. The best option depends on the available reactive groups, whether coupling needs to be directional, and whether the final conjugate should be permanent, cleavable or photoactivated.

Homobifunctional Crosslinkers

Carry the same reactive group on both ends and are useful for amine-to-amine assembly, sulfhydryl-to-sulfhydryl coupling or surface network formation.

DSS / BS3 BS(PEG)9 DSP / DTSSP EGS / DSG

Useful for surface coupling, protein network assembly, multicomponent assays and spacer-optimized biomolecular constructs.

Heterobifunctional Crosslinkers

Provide two different reactive groups, enabling sequential and more controlled coupling between two different partner functionalities.

SMCC Sulfo-SMCC SPDP EMCS BMPS

Commonly used for antibody-oligo conjugates, protein-DNA constructs, peptide-oligo conjugates and nanoparticle attachment.

Amine-Reactive Crosslinkers

Target primary amines such as lysines or terminal amines on proteins, peptides, carriers and surfaces.

NHS Sulfo-NHS TFP STP

Useful for protein labeling, surface immobilization, carrier conjugation and aqueous bioconjugation workflows.

Sulfhydryl-Reactive Crosslinkers

Target cysteine-containing proteins, peptides or engineered thiols for site-directed oligo conjugation.

Maleimide Iodoacetyl Bromoacetyl Pyridyldithiol

Supports robust thioether formation, disulfide exchange or redox-responsive conjugate designs.

Carboxyl-to-Amine Chemistry

Activates carboxyl groups for coupling to primary amines and is commonly used with carboxylated surfaces, beads, proteins or polymers.

EDC NHS Sulfo-NHS

Often selected for surface immobilization, hydrogel coupling and material functionalization.

Aldehyde-Reactive & Photoreactive Handles

Hydrazide/aminooxy handles support aldehyde coupling, while photoreactive groups support UV-triggered proximity capture.

Hydrazide Aminooxy Diazirine Aryl Azide Benzophenone

Used for glycoprotein conjugation, carbohydrate-directed labeling, photoaffinity probes and interaction mapping.

Representative Crosslinkers

Representative Crosslinkers for Oligonucleotide Functionalization

A concise working list of commonly selected crosslinkers and how they are applied to oligonucleotide functionalization.

Crosslinker Reactive Groups Typical Application Oligonucleotide Functionalization Example
SMCC NHS ester / Maleimide Antibody-oligonucleotide conjugates Amine-modified oligo converted to a maleimide-bearing intermediate for cysteine-containing proteins
Sulfo-SMCC NHS ester / Maleimide Water-compatible protein conjugation 5′-amine oligo converted to a maleimide-activated oligo for aqueous conjugation
SPDP NHS ester / Pyridyldithiol Reversible disulfide conjugates Oligo linked to thiol-containing peptides or proteins through cleavable disulfide chemistry
DSS NHS ester / NHS ester Amine-to-amine crosslinking Oligo immobilization to amine-functionalized surfaces or protein assemblies
BS3 NHS ester / NHS ester Water-soluble amine crosslinking Surface conjugation of DNA probes to proteins, carriers or polymer supports
EDC Carboxyl / Amine coupling Carbodiimide-mediated conjugation Carboxyl-modified oligo linked to amine-containing proteins, particles or materials
Sulfo-SANPAH NHS ester / Photoreactive azide Surface immobilization UV-activated attachment of oligonucleotides to biomaterial or assay surfaces
SDA NHS ester / Diazirine Photoaffinity labeling Photo-crosslinkable DNA probes for interaction mapping and proximity capture experiments
Hydrazide Linkers Aldehyde / Hydrazide Glycoprotein and carbohydrate conjugation Hydrazide-modified oligos coupled to oxidized glycans or aldehyde-bearing biomolecules
Workflow & QC

From Chemistry Selection to Analytical Confirmation

Crosslinker-modified oligos should be designed around the partner molecule, attachment site, reaction sequence, purification target and downstream readout.

Compact Crosslinker-Modified Oligonucleotide Workflow Compact workflow showing chemistry selection, handle installation, QC and downstream conjugation. Select Chemistry + partner Install Reactive handle Purify + QC HPLC / MS Conjugate Partner molecule Partner chemistry • spacer architecture • purification strategy • downstream application

Analytical Confirmation

HPLC/UPLC profile, mass confirmation when applicable and COA documentation.

Fit-for-Purpose Purification

Desalting or higher-purity workflow selected around handle stability and downstream use.

Conjugation Readiness

Modification annotation, attachment-position summary and handling notes.

Applications & Downstream Conjugation Workflows

Where Crosslinker-Modified Oligos Are Used

Crosslinker-modified oligonucleotides serve as versatile intermediates for bioconjugation, surface attachment, nanoparticle assembly, affinity capture, and photoactivated molecular interaction studies. Explore common downstream applications supported by Bio-Synthesis.

AOC

Antibody–Oligonucleotide Conjugates

Controlled attachment of oligonucleotides to antibodies and antibody fragments for immuno-PCR, multiplex assays, spatial biology, and targeted biomolecular detection workflows.

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PRO

Protein–DNA Conjugates

Covalent conjugation to proteins, enzymes, carriers, peptides, and affinity reagents for hybrid biomolecular constructs and advanced assay development.

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SUR

Surface Immobilization

Stable attachment of oligonucleotides to glass slides, beads, hydrogels, polymers, biosensor surfaces, and microarray platforms.

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NP

Nanoparticle Conjugation

Functionalized oligonucleotides for gold nanoparticles, polymer nanoparticles, nanomaterials, biosensors, and molecular detection systems.

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CAP

Pull-Down & Capture Tools

Reactive oligo handles for target enrichment, affinity capture, biomolecule isolation, interaction studies, and custom assay development workflows.

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UV

Photo-Crosslinking Probes

Diazirine and other photoreactive oligonucleotide chemistries for UV-triggered interaction capture, photoaffinity labeling, and molecular interaction mapping studies.

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Frequently Asked Questions

FAQ

What information is needed for a quote?
Provide sequence, oligo type, desired crosslinker or reactive class, installation position, conjugation partner, intended application, scale, purification target and QC requirements.
How are crosslinker-modified oligonucleotides used?
They are used to build antibody-oligo conjugates, protein-DNA conjugates, nanoparticle-oligo systems, surface-immobilized probes and photo-crosslinkable nucleic acid probes for diagnostics, biosensors and molecular biology workflows.
Can crosslinker-modified oligonucleotides be used for surface immobilization?
Yes. NHS ester, maleimide, hydrazide, photoreactive and related reactive groups allow oligonucleotides to be covalently attached to glass slides, nanoparticles, hydrogels, polymer supports, beads and microarray surfaces.
What is the difference between homobifunctional and heterobifunctional crosslinkers?
Homobifunctional crosslinkers contain two identical reactive groups. Heterobifunctional crosslinkers contain two different reactive groups, enabling directional coupling between different biomolecular handles.
What are crosslinker-functionalized oligonucleotides?
Crosslinker-functionalized oligonucleotides are DNA or RNA molecules carrying reactive chemical groups that enable covalent coupling to proteins, peptides, polymers, nanoparticles, surfaces or other biomolecules.
Which crosslinker chemistries are commonly used?
Common chemistries include NHS ester amine-reactive linkers, maleimide thiol-reactive reagents, EDC/NHS carbodiimide systems, hydrazide or aminooxy aldehyde-reactive linkers and photoreactive diazirine or benzophenone-style crosslinkers.
More FAQ'sAll FAQ's
Contact & Quote Request

Need help choosing the right crosslinker handle?

Share your sequence, oligo type, requested crosslinker or reactive class, preferred attachment position, quantity, purification target and intended conjugation partner. Bio-Synthesis can help align chemistry, spacer architecture, purification and QC with the downstream workflow.
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Phone: 800-227-0627 (US/CAN)
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Fast Quote Checklist

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Sequence Handle Position Partner QC
Scientific Background & Recommended Reading

Recommended Reading & Literature References

Selected references covering bioconjugation chemistry, crosslinker design, photo-crosslinking, and biomolecular conjugation workflows. These citations are provided for scientific background and design context rather than product-performance claims.

  1. Hermanson GT. Bioconjugate Techniques. 3rd Edition. Academic Press; 2013.
  2. Kalia J, Raines RT. Advances in Bioconjugation. Current Organic Chemistry. 2010;14(2):138-147. DOI
  3. Sinz A. Cross-Linking and Mass Spectrometry to Study Protein Structures and Protein–Protein Interactions. Angewandte Chemie International Edition. 2018;57(22):6390-6396. DOI
  4. Dubinsky L, Krom BP, Meijler MM. Diazirine Based Photoaffinity Labeling. Bioorganic & Medicinal Chemistry. 2012;20(2):554-570. DOI
  5. Dormán G, Prestwich GD. Benzophenone Photophores in Biochemistry. Biochemistry. 1994;33(19):5661-5673. DOI

Note: Crosslinker selection should be based on the available functional groups on both the oligonucleotide and target molecule, reaction conditions, spacer requirements, purification strategy, and intended downstream application. Literature references provide general guidance and should be evaluated within the context of the specific conjugation workflow.

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