Vector Laboratories is closed for the President’s Day on Monday, February 19th. We will be back in the office on Tuesday, February 20th.
We will respond to emails upon our return. Have a wonderful day.

TFP-dPEG®₄-(m-dPEG®₁₁)₃-ester (QBD-11401)



TFP-dPEG®4-(m-dPEG®11)3 ester, product number QBD-11401, is a water-soluble, amine-reactive, discrete PEG (dPEG®) PEGylation reagent built. This product is built around a tris core and consists of a short (21 atoms) amine-reactive 2,3,5,6-tetrafluorophenyl (TFP) ester “”tail”” on a uniform (i.e., monodispersed) PEG4 tail and three (3) medium-length (35 atoms) branches composed from methyl-terminated dPEG®11 (m-dPEG®11). The total dPEG® spacer length from the reactive end to the methyl termini is 63 atoms (74.1 Å average). TFP-dPEG®4-(m-dPEG®11)3 ester is used to PEGylate and modify amine-reactive biomolecules and surfaces. This hydrophilic branched dPEG® product greatly increases the conjugates’ hydrodynamic volumes, reducing immunogenicity and renal clearance. Moreover, this product reduces or eliminates non-specific binding to conjugates and surfaces.

TFP esters react with free amines like NHS esters to form stable amide bonds. TFP esters’ optimal reaction pH is 7.5 – 8.0, which is higher than NHS esters (optimal pH range 7.0 – 7.5). However, published research has shown that, within the optimal reaction pH range, TFP esters are more reactive toward amines than NHS esters are within their optimal pH range. Applications for TFP-dPEG®4-(m-dPEG®11)3 ester, product number QBD-11401, include the following:
conjugating proteins and other biomolecules to modify PK and BD;
PEGylating amine-coated surfaces (e.g., nanoparticles) to sterically shield the surfaces and reduce non-specific, hydrophobic interactions;
PEGylating amine-coated organic or inorganic surfaces (e.g., carbon, gold, silver nanoparticles) to reduce or eliminate immunogenicity;
PEGylating biomolecules to reduce renal clearance and increase serum half-life; and
PEGylating biomolecules to reduce immunogenicity and increase water solubility.


Unit Size100 mg, 1000 mg
Molecular Weight2339.63; single compound
Chemical formulaC₁₀₄H₁₉₁F₄N₅O₄₇
Purity> 96%
SpacersdPEG® Spacer is 63 atoms and 74.1 Å, avg.
Typical solubility properties (for additional information contact Customer Support)Methylene chloride, Acetonitrile, 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.


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.

Synthesis and Preliminary Biological Evaluation of High-Drug-Load Paclitaxel-Antibody Conjugates for Tumor-Targeted Chemotherapy, Sherly Quiles, Kevin P. Raisch, Leisa L. Sanford, James A. Bonner, and Ahmad Safavy, J Med. Chem., 2010, 53 (2), pp 586-594, December 3, 2009. DOI: 10.1021/jm900899g.

Visualizing Systemic Clearance and Cellular Level Biodistribution of Gold Nanorods by Intrinsic Two-Photon Luminescence, Ling Tong, Wei He, Yanshu Zhang, Wei Zheng, and Ji-Xin Cheng, Langmuir 2009, 25 (21), pp 12454-12459. DOI: 10.1021/la902992w.

A New Polyethyleneglycol-Derivatized Hemoglobin Derivative with Decreased Oxygen Affinity and Limited Toxicity. Oana Zolog, Augustin Mot, Florina Deac, Alina Roman, Eva Fischer-Fodor, Radu Silaghi-Dumitrescu. The Protein Journal. 2010 1 (30), pp 27-31. December 16, 2012 DOI: 10.1007/s10930-010-9298-5.

Improved pharmacokinetics and immunogenicity profile of organophosphorus hydrolase by chemical modification with polyethylene glycol. Boris N. Novikov, Janet K. Grimsley, Rory J. Kern, James R. Wild, Melinda E. Wales. Elsevier. 2010 146 (3) Pages 318-325 September 15, 2010. DOI: 10.1016/j.jconrel.2010.06.003.

Applicable patents and legal notices are available at legal notices.

How do I Request a Quote?

To request a quote for products:

  1.  Log in to
  2.  Add the items you wish to quote to the cart;
  3.  View your cart;
  4.  Click on the “Request a Quote” button found below the items in your cart;
  5.  Download your quote