m-dPEG®₁₃-NHS ester

m-dPEG®13-NHS ester, product number 11086, is a medium length, methyl-terminated, discrete length polyethylene glycol (dPEG®) spacer. With a reactive end as the N-hydroxysuccinimidyl (NHS) ester, m-dPEG®13-NHS ester is designed to modify surfaces containing accessible free amines. Except for the reactive end group, this product is essentially identical to m-dPEG®13-TFP ester, product number 11087.



Free amines react optimally at pH 7.2 – 7.5 in aqueous media with NHS esters. Moreover, in aqueous media, the hydrolytic rate of the ester to the carboxylic acid increases with increasing pH. Reacting 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.

There are numerous potential applications that could appropriately employ m-dPEG®13-NHS ester. Such applications include:

cell surface engineering;
PK and immunogenicity improvements dendrimers, peptides, and proteins;
imaging applications to reduce background and non-specific binding;
dendrimer construction;
peptide synthesis and modification to improve water solubility or to decrease immunogenicity;
coating of nanoparticles, quantum dots, and carbon nanotubes; and,
prevention of enzyme aggregation.

m-dPEG®13-NHS ester, product number 11086, is just one member of an comprehensive line of methyl-terminated dPEG® products. This line includes dPEG® spacers containing 2 to 49 ethylene glycol units. These products are functionalized with NHS or with 2,3,5,6-tetrafluorophenol (TFP). TFP has proven to be superior to NHS for amine-reactive products.

Quanta BioDesign, Ltd., makes and sells single molecular weight PEG linkers and spacers with discrete chain lengths under the trade name dPEG®. Our products are distinctly different from traditional PEG products in that they are not disperse polymers. However, they confer all of the benefits of traditional PEG products.

Please contact us at for specific academic pricing.