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EZ-Link TFPA-PEG3-Biotin

High-efficiency, photoreactive biotinylation reagent.

EZ-Link TFPA-PEG3-Biotin TFPA-PEG3-Biotin

Thermo Scientific EZ-Link TFPA-PEG3-Biotin is an efficient, photoactivatable reagent based on tetrafluorophenyl azide for biotinylation and includes a 3-unit polyethylene glycol (PEG) spacer arm.

TFPA-PEG3-Biotin is a photoactivatable reagent for biotinylation of antibodies, proteins and many other kinds of macromolecules. The tetrafluorophenyl azide (TFPA) group activates upon exposure to UV-Light (maximum absorptivity is at 320 nm) to insert covalently at sites containing C-H or N-H bonds. The hydrophilic polyethylene glycol (PEG) spacer arm imparts water solubility that is transferred to the biotinylated molecule, thus reducing aggregation of labeled molecules stored in solution. The PEG spacer arm also gives this reagent a long and flexible connection to minimize steric hindrance involved with binding to avidin molecules.


  • Biomolecular labeling – biotinylate proteins, DNA, RNA and many other macromolecules, even if they do not possess primary amines or sulfhydryl groups
  • Photo-reactive – perfluorophenyl azido group activates upon exposure to ultraviolet light to form covalent bonds with nucleophiles and many other chemical groups
  • Pegylated – spacer arm contains a hydrophilic, 3-unit, polyethylene glycol (PEG) group
  • Enhances solubility – pegylation imparts water solubility to the biotinylated molecule, helping to prevent aggregation of biotinylated antibodies stored in solution
  • Irreversible – forms permanent thioether bonds; spacer arm cannot be cleaved
  • Solubility – best to dissolve in DMSO or DMF before further dilution in aqueous buffers
  • Long reach – spacer arm (total length added to target) is 33.4 angstroms, minimizing steric hindrance for binding interactions with streptavidin

Product Details:

Chemical structure of TFPA-PEG3-Biotin, tetrafluorophenyl azide biotin
Chemical structure of TFPA-PEG3-Biotin. This perfluorophenyl azide biotinylation reagent covalently attaches to proteins and other molecules upon photo-activation with UV-light. For more information, see our review of Aryl Azide Reaction Chemistry.

Properties of TFPA-PEG3-Biotin. This photo-activatable compound has an extended, pegylated spacer arm terminated by a tetrafluorophenyl azide reactive group.
Alternative names TFPA-PEO3-Biotin; TFPA-dPEG3-Biotin; dPEG-Biotin TFPA
Chemical name (simplified) Biotinamido-[tri(ethylene glycol)]-azido-2,3,5,6-tetrafluorobenzamide
Molecular formula C27H37F4N7O6S
Molecular weight 663.69
Spacer arm length 33.4 angstroms
Mass added to target Several products possible
Form White to off-white solid
Storage conditions 4°C protected from light
Reactive groups Tetrafluorophenyl azide, reacts upon exposure to ultraviolet light

We manufacture biotin reagents to ensure the highest possible overall product integrity, consistency and performance for the intended research applications.

Biotinylation reagents differ in reactivity, length, solubility, cell permeability and cleavability. Several different types of photoreactive compounds are available. Aryl azide reagents activate upon exposure to ultraviolet light initiate addition reactions with double bonds, insertion into C–H and N–H sites, or subsequent ring expansion to react with a nucleophile (e.g., primary amines).


  • Hermanson, G.T. (2008). Bioconjugate Techniques. Academic Press. (Part No. 20036).
  • Pandurangi, R.S., et al. (1998). Chemistry of bifunctional photoprobes: Part 4: Synthesis of the chromogenic, cleavable, water soluble and heterobifunctional (N-Methyl amino perfluoroaryl azide benzamido)-ethyl-1,3-dithiopropionyl sulfosuccinimide: An efficient protein cross-linking agent. Bioorganic Chem. 26(4):201-12.
  • Pandurangi, R.S., et al. (1997). Recent trends in the evaluation of photochemical insertion characteristics of heterobifunctional perfluoroaryl azide chelating agents: Biochemical implications in nuclear medicine. Photochem. Photobiol. 65(2):208-21.
  • Pandurangi, R.S., et al. (1997). Chemistry of bifunctional photoprobes: Part 1. Perfluoro azido functionalized phosphorus hydrazides as novel photoreactive heterobifunctional chelating agents: High efficiency nitrene insertion on model solvents and proteins. J. Org. Chem. 62(9):2798-807.
  • Pandurangi, R.S., et al. (1996). Preservation of immunoreactivity in the photolabeling of B72.3 human antibody. Photochem. Photobiol. 64(1):100-5.
  • Pandurangi, R.S., et al. (1995). Photolabeling of human serum albumin by 4-azido-2-(14C-Methylamino) trifluorobenzonitrile. A high-efficiency long wavelength photolabel. App. Rad. Isot. 46(4): 233-9.
  • Pandurangi, R.S., et al. (1995). High efficiency photolabeling of human serum albumin and human g-globulin with [14C]Methyl 4-azido-2,3,5,6-tetrafluorobenzoate. BioConjugate Chem. 6: 630-4.
  • Yan, M., et al. (1994). N-Hydroxysuccinimide ester functionalized perfluorophenyl azides as novel photoactive heterobifunctional cross-linking reagents.The covalent immobilization of biomolecules to polymer surfaces. Bioconjugate Chem. 5: 151-7.
  • Platz, M.S. et. al. (1993). Synthesis and binding of new polyfluorinated aryl azides to alpha-Chymotrypsin. New reagents for photoaffinity labeling. Bioconjugate Chem. 4: 256-261.
  • Platz, M.S. et al. (1992). Chemistry and Kinetics of singlet (pentafluorophenyl)nitrene. J. Amer. Chem. Soc. 114: 5054-5067.

Related Resources:

Biotinylation Reagents Selection Guide
Review of Biotinylation Methods and Applications
Chemistry of Crosslinking (and Labeling Reagents)

Related Products:

All Biotinylation Reagents
Avidin, Streptavidin, NeutrAvidin Affinity Resins

Ordering Information
Product # Description Pkg. Size Instructions MSDS CofA Price
21303 EZ-Link TFPA-PEG3-Biotin
Formulation: Tetrafluorophenyl azide of biotin with a triethyleneglycol spacer
Sufficient For: Approx. 12 uses to label a total of 251mg of IgG using typical conditions
25mg Product Instructions for product #21303 EZ-Link TFPA-PEG3-Biotin MSDS for product #21303 EZ-Link TFPA-PEG3-Biotin Certificate of Analysis for product #21303 EZ-Link TFPA-PEG3-Biotin $213.00

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Instructions | MSDS | CofA
Product Instructions | MSDS | CofA  

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