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Biotin-dPEG®₄-TFP ester (QBD-10009)


Biotin-dPEG®4-TFP ester is an amine-reactive biotinylation reagent with optimal reactivity in the pH range of 7.5 – 8.5. The TFP ester is more hydrolytically stable than the corresponding NHS ester, providing better labeling of peptides, proteins, and other biomolecules.


Biotin-dPEG®4-TFP ester, product number QBD-10009, is an amine-reactive, water-soluble biotin label functionalized with a hydrolytically stable 2,3,5,6-tetrafluorophenyl ester. The single molecular weight PEG4 (dPEG®4) linker is longer than the aminocaproic acid linker of LC-biotin and slightly longer than the two conjugated aminocaproic acid linkers of LC-LC-biotin, allowing for better interaction with the biotin-binding pockets of avidin and streptavidin. Furthermore, unlike traditional LC linkers, the dPEG® linker is flexible and hydrophilic, eliminating biotinylated protein aggregation proteins over time. The TFP ester is more hydrolytically stable than classic NHS esters and has an optimum pH range of 7.5 – 8.5 for conjugating to free amines.


Unit Size 100mg, 1000mg
Molecular Weight 639.66; single compound
Chemical formula C₂₇H₃₇ F₄N₃O₈S
Purity > 98%
dPEG® Spacer is 16 atoms and 19.2 Å
Typical solubility properties (for additional information contact Customer Support) Methylene chloride, DMAC or DMSO.
Storage and handling
-20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.


  1. Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0). Specifically see pp. 726-729 in his chapter 18 on discrete PEG compounds.

  2. Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Applicable patents and legal notices are available at legal notices.

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