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.

m-dPEG®₂-NHS ester (QBD-10327)



m-dPEG®2-NHS ester, product number QBD-10327, is a short (8 atoms, 8.5 Å), methyl-terminated, discrete-length polyethylene glycol (dPEG®) spacer, functionalized as the N-hydroxysuccinimidyl (NHS) ester and designed for modification of surfaces containing accessible free amines. NHS reacts optimally with free amines at pH 7.0 – 7.5. The active ester’s rate of hydrolysis to the carboxylic acid accelerates with increasing pH. Please note that modification of surface amines on biomolecules (e.g., proteins and peptides) with this uncharged, methyl-capped dPEG® spacer may alter the overall charge of the resulting conjugates.

One potential application for this product include charge modification of a biomolecule by modifying positively charged free amines with the uncharged m-dPEG®2-NHS ester. Another potential application is to use m-dPEG®2-NHS ester in a mixed surface modification (for example, an amine-coated glass or silica surface) where the shorter dPEG® product passivates the surface while longer dPEG® products contain reactive groups for additional functionalization of the surface. Other potential or published applications for this product include the following:
surface modification of silica-shelled quantum dots;
coating of carbon nanotubes and other hydrophobic surfaces;
N-terminal peptide modification; and
various imaging applications.


Unit Size100 mg, 1000 mg
Molecular Weight245.23; single compound
Chemical formulaC₁₀H₁₅NO₆
Purity> 98%
SpacersdPEG® Spacer is 8 atoms and 8.5 Å
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.

Short polyethylene glycol chains densely bound to soft nanotube channels for inhibition of protein aggregation. N. Kameta, T. Matsuzawa, K. Yaoi, and M. Masuda. RSC Advances. 2016, 6 (43) pp 36744-36750. April 7, 2016. DOI: 10.1039/C6RA06793J.

Hairpin Structure of a Biarsenical- Tetracysteine Motif Determined by NMR Spectroscopy, Fatemeh Madani, Jesper Lind, Peter Damberg, Stephen R. Adams, Roger Y. Tsien, and Astrid O. Graslund. JACS (J. Am. Chem. Soc.). 2009, 131 (13), pp 4613–4615. March 12, 2009. DOI: 10.1021/ja809315x.

Silica-Shelled Single Quantum Dot Micelles as Imaging Probes with Dual or Multimodality. Rumiana Bakalova, Zhivko Zhelev, Ichio Aoki, Hideki Ohba, Yusuke Imai, and Iwao Kanno. Anal. Chem. 2006, 78 (16) pp 5925–5932. July 14, 2006. DOI: 10.1021/ac060412b.

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