m-PEG4-NH-DBCO | CAS 2228857-36-9

m-PEG4-NH-DBCO is a difunctional, PEG-tethered cyclooctyne click reagent that incorporates a DBCO (dibenzocyclooctyne) strained-alkyne handle for copper-free strain-promoted azide–alkyne cycloaddition (SPAAC). The para-positioned PEG4 spacer and terminal amine enable straightforward conjugation to biomolecules, surfaces, and polymer scaffolds, while the DBCO moiety provides high selectivity toward azide-containing partners under mild conditions. This combination makes m-PEG4-NH-DBCO a widely used reagent for building stable, site-specific conjugates for chemical biology workflows, probe development, and functional material assembly.

1. Protein And Peptide Labeling

m-PEG4-NH-DBCO is commonly used to generate azide-functional protein and peptide conjugates for imaging, pull-down, and analytical workflows where a copper-free click handle is preferred. The PEG4 spacer helps reduce steric hindrance and improves accessibility of the DBCO group during conjugation to azide-bearing targets such as azide-labeled antibodies, enzyme tags, or engineered proteins. Researchers also leverage the terminal amine functionality to attach the reagent to activated carriers or to introduce the DBCO-bearing linker into protein labeling strategies, supporting reproducible probe preparation for downstream assays and characterization.

2. Antibody Conjugation Platforms

m-PEG4-NH-DBCO is frequently incorporated into antibody conjugation platforms that rely on azide–alkyne click chemistry to install fluorescent dyes, affinity tags, or functional payloads onto IgG scaffolds. The PEG4 tether improves conjugate solubility and can mitigate nonspecific interactions that sometimes arise from overly hydrophobic linkers, which is valuable when preparing antibody reagents for multiplexed labeling or workflow compatibility with common bioconjugation buffers. By pairing with azide-functional secondary reagents or azide-modified antibody fragments, suppliers and research groups can produce well-defined antibody–probe constructs used in biochemical studies and molecular imaging reagent development.

3. Surface And Material Functionalization

m-PEG4-NH-DBCO is used to functionalize polymers, nanoparticles, and solid supports with SPAAC-reactive DBCO groups, enabling subsequent coupling to azide-modified coatings, biomolecules, or capture ligands. The PEG4 spacer supports colloidal stability and helps maintain reactive group accessibility on complex surfaces, which is particularly relevant for building reusable diagnostic reagent surfaces, biosensor interfaces, and cell-adhesive or bioinert material systems. In industrial and materials R&D settings, m-PEG4-NH-DBCO is selected for its ability to form stable triazole linkages under copper-free conditions, supporting integration into workflows where metal-free labeling is advantageous for sensitive components.

4. Molecular Imaging Probe Assembly

m-PEG4-NH-DBCO is a standard reagent for assembling azide-functional molecular imaging probes, including fluorescent and luminescent conjugates, where modular coupling is needed to rapidly swap targeting or reporting components. The DBCO handle enables efficient SPAAC pairing with azide-bearing probe precursors, while the PEG4 linker helps tune hydrophilicity and reduce aggregation during probe formulation and purification. Chemical biology teams and imaging reagent developers use m-PEG4-NH-DBCO to build probe libraries, enabling consistent attachment of reporter moieties, affinity elements, or polymeric carriers to create imaging-ready conjugates for instrument-based characterization and method development.