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Biotinylate azide-tagged molecules for detection or purification.

Pierce Biotin-PEG3-Phosphine

Thermo Scientific Pierce Phosphine-PEG3-Biotin is a biotinylation reagent for labeling azide-containing molecules, which enables biotin-based detection and affinity purification of molecules via Staudinger ligation strategies.

When used in combination with azide labeling strategies, this compound enables detection or affinity purification of protein interactions and post-translational modifications using streptavidin probes or streptavidin agarose resins. The phosphine group of Phosphine-PEG3-Biotin conjugates to azide groups by the Staudinger reaction mechanism. Azide groups can be introduced into proteins or other cellular targets through in vivo labeling with azide-tagged derivatives of naturally occurring metabolic building blocks. Because neither phosphines nor azides are present in biological systems, they comprise a chemoselective (mutually specific) ligation pair for labeling and conjugation.


  • Soluble – easily dissolves in water-miscible solvents (e.g., DMSO) for subsequent dilution in aqueous reaction mixtures with cell lysates and other biological samples
  • Compatible – reaction chemistry occurs effectively in simple buffer conditions; requires no accessory reagents such as copper or reducing agents
  • Chemoselective – the phosphine reactive group is specific in biological samples for bioorthogonal azide-tagged molecules, ensuring that biotinylation is specific
  • PEG spacer – polyethylene glycol spacer arm helps maintain solubility of labeled molecules and decreases steric hindrance for affinity-binding to avidin, streptavidin or NeutrAvidin Protein

Product Details:

Chemical structure of Biotin-PEG3-Phosphine, a Staudinger ligation reagent
Chemical structure of Phosphine-PEG3-Biotin. This biotinylation reagent is for labeling and detection of azide-tagged molecules via the Staudinger ligation reaction chemistry.

Properties of Phosphine-PEG3-Biotin.
Alternative names Phosphine-PEO3-Biotin, Phosphine-dPEG3-Biotin
Molecular formula C41H53N4O8PS
Molecular weight 792.92
Spacer arm length 33.0 angstroms
Form Light yellow to yellow powder
Storage conditions -20°C
Reactive groups Phosphine, reacts with azide groups

Biotin labeling of azide-tagged glycoproteins
Example strategy for in vivo metabolic labeling with biotin using Phosphine-PEG3-Biotin. When bioorthogonal azido-sugar derivatives are supplied to living cells, they become incorporated into glycoprotein structures by endogenous post-translational modification mechanisms. The azide-tagged molecules can then be selectively labeled or conjugated to phosphine-activated molecules, in this case, a derivative of biotin. If the azido sugars were supplied to cells being studied for response to a particular treatment, the biotin affinity-tag could be used to purify and analyze differences in glycosylation resulting from the treatment regime.

Related Resources:

Azide-Phosphine Reagent Guide
Review of Metabolic Labeling for Chemoselective Ligation
Review of Staudinger Ligation Reaction Chemistry
Superiority of Azide-Phosphine Chemistry

Related Products:

Azide-Sugars for Metabolic Labeling and Detection
NHS-Azide Staudinger Ligation Reagents
NHS-Phosphine Staudinger Ligation Reagents
Phosphine-activated DyLight Fluors

Ordering Information
Product # Description Pkg. Size Instructions MSDS CofA Price
88901 EZ-Link Phosphine-PEG3-Biotin
Formulation: Phosphine-activated biotin with a triethyleneglycol spacer
Sufficient For: Labeling a total of 80mg of azide-labeled protein using typical conditions
10mg Product Instructions for product #88901 EZ-Link Phosphine-PEG3-Biotin MSDS for product #88901 EZ-Link Phosphine-PEG3-Biotin Certificate of Analysis for product #88901 EZ-Link Phosphine-PEG3-Biotin $427.00

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Instructions | MSDS | CofA
Product Instructions | MSDS | CofA  

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