Biotin-PEG3-Azide | CAS 875770-34-6

Biotin-PEG3-Azide is a biotinylated azide reagent featuring a short polyethylene glycol (PEG3) spacer that improves solubility and reduces steric constraints in labeling workflows. As an azide-bearing click chemistry handle, it is commonly used in copper-free or copper-catalyzed azide–alkyne cycloaddition formats to install biotin onto biomolecules, surfaces, and polymeric materials. The PEG spacer and biotin affinity make Biotin-PEG3-Azide particularly relevant for affinity capture, pull-down assays, and downstream detection of labeled targets in chemical biology and materials research.

1. Biotinylation For Proteomics

Biotin-PEG3-Azide is widely used to introduce a biotin tag onto proteins, peptides, or protein complexes for enrichment-based proteomics workflows. Researchers incorporate the azide handle into labeling strategies so that subsequent click coupling to complementary alkyne reagents enables selective capture on streptavidin or neutravidin matrices. The PEG3 spacer helps maintain accessibility of the biotin moiety during binding and supports robust recovery of labeled species from complex lysates, supporting applications such as sample fractionation, target enrichment, and comparative profiling of biomolecular populations.

2. Cell Surface Labeling Probes

Biotin-PEG3-Azide is commonly employed in chemical biology to functionalize cell-surface glycans, receptors, or other membrane-associated targets through click-compatible labeling schemes. The azide functionality serves as a modular attachment point that can be coupled to alkyne-bearing reporters, including fluorescent or affinity tags, enabling researchers to map biomolecular distribution with biotin-based readouts. The PEG3 linker contributes to reduced steric hindrance and improved labeling uniformity, which is valuable when preparing samples for streptavidin-based detection, imaging workflows, or pull-down of labeled membrane components.

3. Affinity Capture Of Biomaterials

Biotin-PEG3-Azide is used to incorporate biotin functionality into biomaterial surfaces and polymer constructs, providing a convenient affinity handle for subsequent immobilization or capture steps. In materials and molecular imaging research, the azide group enables click conjugation to alkyne-functional linkers, coatings, or reporter molecules, while the biotin moiety supports strong and specific binding to avidin-family proteins. This combination is frequently applied to create modular platforms for immobilizing enzymes, binding proteins, assembling multilayer materials, or generating standardized affinity capture reagents for analytical and workflow development.

4. Diagnostic And Assay Reagent Building

Biotin-PEG3-Azide serves as a practical building block for preparing affinity reagents used in assay development and analytical toolchains that rely on biotin–avidin interactions. Laboratories use the azide handle to couple biotin to alkyne-functional detection reagents, enabling flexible construction of capture probes, standardized reagent conjugates, and multivalent affinity formats. The PEG3 spacer helps preserve accessibility of both the biotin binding site and the conjugated partner, which supports consistent performance in binding-based assay workflows such as enrichment, separation, and signal readout preparation.