Vector Labs is closed to observe Independence Day (US Holiday) on Thursday, July 4th.
We will be back in the office on Friday. We will respond to emails upon our return. Have a wonderful day.

Tetra(-amido-dPEG®₂₃-MAL)pentaerythritol (QBD-11414)



Tetra(-amido-dPEG®23-MAL)pentaerythritol, product number QBD-11414, is a maleimide-functionalized PEG crosslinking reagent designed to join up to four molecules via a maleimide-thiol reaction. Each of the four arms of this product comes from a single molecular weight, discrete polyethylene glycol (dPEG®) spacer that is 79 atoms (89.8 Å) long, joined through a pentaerythritol core. Product applications include (1) crosslinking of proteins, peptides, or small molecules containing free sulfhydryl groups and (2) dendrimer construction with thiol-functionalized branched compounds.

The thiol-maleimide reaction, also known as the thiol-Michael addition, is a click chemistry reaction. This powerful, highly popular reaction is extensively used in bioconjugation applications. At pH 6.5 – 7.5, the thiol-maleimide reaction is chemoselective. However, above pH 7.5, the maleimide group reacts competitively with amines, so the pH should be kept below this limit.

Unlike traditional polyethylene glycol (PEG), which are non-uniform, dispersed polymers, Vector Laboratories’ dPEG® products are single molecular weight PEGs with discrete chain lengths, hence the dPEG® name.

Tetra(-amido-dPEG®23-MAL)pentaerythritol showcases one of the benefits of dPEG® linkers in product development. Each of the four dPEG® arms is identical, and the uniformity simplifies analysis. In contrast, if this product were made using traditional, non-uniform PEG compounds, analyzing it would be much more complicated and challenging.


Unit Size25 mg, 100 mg
Molecular Weight5250.04; single compound
Chemical formulaC₂₃₇H₄₄₀N₁₂O₁₁₂
Purity> 96%
SpacersdPEG® Spacer for each arm is 79 atoms and 89.8 Å
Typical solubility properties (for additional information contact Customer Support)Water, dimethylacetamide(DMAc), methanol, or DCM
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, 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 for pegylation applications.

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.

How do I Request a Quote?

To request a quote for products:

  1.  Sign 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