Biotin-PEG2-CH2CH2-azide
Molecular Formula: C16H28N6O4S
CAS#: 945633-30-7
SMILES: O=C1N[C@]([C@]([H])(CS2)N1)([H])[C@@H]2CCCCC(NCCOCCOCCN=[N+]=[N-])=O
MDL#: MFCD26142991
Catalog#: AMTGC857-BA21
Molecular weight: 400.50 g/mol
Appearance: Yellow solid
Purity: 97%
Storage: Roo temperature
Solubility: Solubility is poor in most organic solvents.
Other names:
- N-(2-(2-(2-azidoethoxy)ethoxy)ethyl)-5-((3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanamide
- Biotin-PEG2-N3
- Biotin-PEG2-CH2CH2N3
- (+)-Biotin-PEG2-azide
- Biotin-NH-PEG2-N3
Fields of Interest
Click chemistry, bioconjugation, biotinylation, chemical biology, affinity labeling, proteomics, biomolecule detection, molecular imaging, diagnostics research, surface functionalization, probe development, drug discovery
Background
Biotin-PEG2-azide (CAS 945633-30-7) is a heterofunctional biotinylation reagent that combines a biotin affinity tag, a short, hydrophilic PEG2 spacer, and a terminal azide (N₃) group. The biotin moiety provides high-affinity recognition by avidin- and streptavidin-based systems, while the oligoethylene glycol spacer introduces flexibility and separation between the biotin group and a conjugated target.
The terminal azide provides a bioorthogonal reaction handle for copper-catalyzed azide–alkyne cycloaddition (CuAAC) with terminal alkynes and strain-promoted azide–alkyne cycloaddition (SPAAC) with strained cyclooctynes such as DBCO and BCN. This combination of affinity recognition and click reactivity makes Biotin-PEG2-azide a versatile building block for labeling, detection, enrichment, and molecular assembly.
Applications
Biotin-PEG2-azide is useful in bioconjugation, chemical biology, affinity labeling, proteomics, biomolecule detection, surface functionalization, and probe development. Through CuAAC or SPAAC, the terminal azide can be used to attach biotin to appropriately functionalized proteins, peptides, oligonucleotides, carbohydrates, small molecules, polymers, or surfaces.
Following conjugation, the biotin functionality enables interaction with streptavidin or avidin systems for affinity capture, enrichment, immobilization, purification, or detection. The defined PEG spacer provides molecular separation between biotin and the attached target while maintaining a compact linker architecture. Biotin-PEG2-azide can therefore be useful in the construction of affinity probes and other multifunctional molecular systems requiring both click chemistry and biotin recognition.
Literature:
- Chemical Communications, 2014, vol. 50, # 23, p. 3044 – 3047
- Journal of Medicinal Chemistry, 2026, vol. 69, # 11, p. 13856 – 13873
- Bioorganic and Medicinal Chemistry Letters, 2019, vol. 29, # 2, p. 234 – 237