N-DBCO-N-bis(PEG2-C2-NHS ester) | CAS 2128735-29-3

N-DBCO-N-bis(PEG2-C2-NHS ester) is a dual-function click chemistry reagent that combines a strained-alkyne DBCO handle with two NHS-ester groups for rapid amine-reactive labeling. As a widely used DBCO-based cycloaddition partner, it enables copper-free strain-promoted azide–alkyne cycloaddition (SPAAC) in bioconjugation workflows, while the PEG2-C2-NHS esters provide water-compatible, spacing-tuned attachment to primary amines on proteins, peptides, and other amine-bearing biomolecules. This combination makes the reagent particularly relevant for building azide-functional probes, imaging reagents, and modular biomaterials where controlled multivalent conjugation and subsequent click coupling are required.

1. Protein Labeling And Conjugation

N-DBCO-N-bis(PEG2-C2-NHS ester) is commonly used to introduce DBCO functionality onto amine-containing proteins, antibodies, and antibody fragments through NHS-ester chemistry, generating azide-reactive conjugates for downstream SPAAC assembly. The PEG2-C2 spacer design helps reduce steric crowding around the reactive sites, which is valuable when preparing labeled binding reagents for flow cytometry, microscopy, and assay development. Researchers frequently use this reagent to create multivalent protein conjugates where the DBCO handle is installed in a controlled manner before coupling to azide-bearing targets such as affinity tags, nanoparticles, or imaging scaffolds.

2. Multivalent Surface Functionalization

N-DBCO-N-bis(PEG2-C2-NHS ester) supports modular functionalization of amine-presenting surfaces and biomaterial interfaces, including polymer coatings, derivatized beads, and hydrogel components bearing primary amines. By installing DBCO groups via NHS ester reactivity, the reagent enables subsequent SPAAC coupling to azide-functional ligands, reporters, or crosslinking partners, allowing stepwise construction of complex, addressable materials. This workflow is widely adopted in materials chemistry and chemical biology labs to create clickable surfaces with improved accessibility, where PEG-based spacing can help maintain binding and coupling efficiency at the interface.

3. Imaging Probe And Reporter Assembly

N-DBCO-N-bis(PEG2-C2-NHS ester) is frequently selected for preparing DBCO-functional imaging and reporter conjugates that can be rapidly assembled with azide-containing dyes, fluorophores, or luminescent tags using copper-free click chemistry. The dual NHS-ester functionality allows direct conjugation to amine-bearing carriers such as proteins, peptides, or other scaffold molecules, while the DBCO moiety provides a robust handle for orthogonal coupling to azide reporters. This approach is particularly useful in molecular imaging reagent development and diagnostic-reagent research, where modularity and reproducible conjugate construction are important for generating consistent probe formats.

4. Targeting Ligand Modular Construction

N-DBCO-N-bis(PEG2-C2-NHS ester) is well suited for building targeting-ligand conjugates in which a DBCO-bearing targeting scaffold is prepared first and then coupled to azide-functional payloads. The NHS ester groups enable attachment to amine-rich targeting components such as peptides, engineered binding domains, and carrier proteins, while the DBCO handle supports SPAAC coupling to azide-bearing partners including affinity handles, enrichment tags, or reporter modules. In chemical biology and biomarker-assay development, this modular strategy helps teams rapidly generate families of conjugates with consistent click-ready chemistry, supporting systematic optimization of labeling density and construct architecture.