NHS-PEG5-tris-PEG3-azide

NHS-PEG5-tris-PEG3-azide is a PEG-based amine-reactive click chemistry reagent that combines an N-hydroxysuccinimide (NHS) ester for efficient conjugation to primary amines with a terminal azide handle for subsequent copper-free or copper-mediated azide–alkyne cycloaddition workflows. The tris-PEG architecture provides multivalent spacing and improved solubility for building stable, well-defined bioconjugates, which is commonly leveraged in labeling, surface functionalization, and probe/material assembly. This reagent is frequently selected in chemical biology and biomaterials pipelines where controlled PEGylation and a downstream clickable azide are both required.

1. Protein PEGylation Labeling

NHS-PEG5-tris-PEG3-azide is widely used to introduce a PEG spacer onto lysine-containing proteins while simultaneously installing an azide functional group for later conjugation to fluorescent dyes, affinity tags, or imaging moieties. Researchers in proteomics, chemical biology, and assay development often choose this format to improve conjugate solubility and reduce nonspecific interactions, while keeping a single, orthogonal click handle for modular assembly. The PEG-mediated spacing also helps maintain accessibility of the azide for subsequent bioconjugation steps, supporting workflows that require consistent labeling density across protein batches.

2. Antibody and Ligand Conjugates

NHS-PEG5-tris-PEG3-azide supports fabrication of antibody and binding-ligand conjugates where amine-reactive PEGylation is used to tune conjugate properties and provide a defined azide handle for modular attachment of detection or capture components. Immunoassay and molecular imaging research groups commonly apply this reagent to prepare azide-functional antibody derivatives that can be linked to alkyne-bearing reporters, nanoparticles, or multivalent scaffolds through click chemistry. The tris-PEG spacing is particularly useful when downstream conjugation requires the reactive group to remain accessible after protein immobilization or formulation.

3. Surface and Nanoparticle Functionalization

NHS-PEG5-tris-PEG3-azide is used to functionalize amine-bearing surfaces and nanoparticle platforms with azide-terminated PEG linkers, enabling subsequent attachment of alkyne-functional ligands, polymers, or fluorescent reporters. Materials scientists and industrial R&D teams often incorporate this reagent into coating and surface-chemistry workflows to create stable, hydrated interfaces that reduce aggregation and improve reproducibility. By installing azide groups through NHS ester chemistry, the resulting surfaces can be rapidly decorated via click reactions, supporting scalable production of labeled materials and reusable diagnostic-reagent formats.

4. Multivalent Probe and Scaffold Assembly

NHS-PEG5-tris-PEG3-azide is a practical building block for constructing multivalent chemical probes and PEG-based scaffolds that require both amine-reactive installation and a terminal azide for orthogonal coupling. Chemical biology laboratories use the reagent to prepare azide-functional components that can be assembled into higher-order architectures such as polymeric networks, branched probe libraries, or modular affinity constructs using alkyne-bearing partners. The PEG-rich, tris-PEG design helps maintain flexibility and steric accessibility, which is valuable when assembling probes intended for sensitive surface-dependent labeling or for generating structured reagent libraries for imaging and diagnostics development.