DBCO-PEG8-NHS ester | CAS 2553412-88-5

DBCO-PEG8-NHS ester is a dibenzocyclooctyne (DBCO) functionalized, PEG8-linked NHS ester designed for strain-promoted azide–alkyne cycloaddition (SPAAC) bioconjugation workflows. The DBCO group enables catalyst-free click coupling with azide-bearing biomolecules or materials, while the NHS ester provides efficient amine-reactive labeling for attaching the click handle to proteins, peptides, and other primary-amine-containing substrates. This combination makes it a widely used reagent for building modular conjugates used in chemical biology, molecular imaging, and biomaterials research where orthogonal, high-yield conjugation and subsequent click coupling are required.

1. Protein Surface Labeling

DBCO-PEG8-NHS ester is commonly used to introduce a SPAAC-compatible DBCO click handle onto proteins and protein-derived reagents via NHS ester chemistry toward lysine and N-terminal amines. Researchers use the resulting DBCO-functionalized proteins as versatile building blocks for downstream coupling to azide-functional targets, including cell-surface ligands, affinity reagents, and imaging tags. The PEG8 spacer helps reduce steric hindrance and can improve accessibility of the DBCO group during subsequent azide click reactions, supporting consistent conjugation in complex biological labeling workflows.

2. Antibody and Ligand Conjugation

DBCO-PEG8-NHS ester is frequently selected for preparing azide-reactive antibody conjugates and ligand-based targeting constructs, where a defined click handle is required for later assembly. By first installing DBCO onto antibody frameworks or other targeting ligands through NHS ester reactivity, teams can then perform SPAAC coupling to azide-bearing payloads such as fluorescent dyes, affinity moieties, or polymeric scaffolds. This two-step modular strategy is especially useful when payloads are introduced at a later stage, enabling flexible design of multicomponent probes and reducing constraints on labeling order.

3. Imaging Probe Assembly

DBCO-PEG8-NHS ester supports the construction of molecular imaging reagents by enabling rapid attachment of click handles to amine-containing targeting components that will be coupled to azide-functional imaging reporters. In practice, the reagent is used to generate DBCO-modified probes that can be assembled with azide-bearing fluorophores or other reporter platforms under catalyst-free conditions, facilitating streamlined probe preparation for microscopy, flow-based assays, and imaging reagent screening. The PEG8 linker is often leveraged to improve conjugate solubility and maintain reporter accessibility, which is important when assembling multivalent imaging constructs.

4. Biomaterials Functionalization

DBCO-PEG8-NHS ester is widely applied to functionalize biomaterials and surfaces that present primary amines, including polymer coatings, hydrogel components, and amine-derivatized scaffolds. After coupling the NHS ester to amine groups, the resulting DBCO-functional materials can be patterned or modified through SPAAC with azide-bearing biomolecules, peptides, or bioactive ligands to create clickable interfaces. This approach is used to generate modular materials for research-grade biosensing, cell-interaction studies, and engineered microenvironments where spatial or temporal control of ligand presentation is advantageous.