MAL-dPEG®₄-TFP ester

MAL-dPEG®4-TFP ester, product number 10551, is a crosslinking reagent that joins free amines to free thiols (sulfhydryl groups). The sulfhydryl groups react with a maleimido group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the 2,3,5,6-tetrafluorophenyl (TFP) ester of the terminal propionic acid group. The maleimido and TFP functional groups on the crosslinking compound sit at either end of a short, discrete chain of polyethylene glycol (hence, dPEG®).

Crosslinking Reactions
One of the most popular, most useful crosslinking reactions in bioconjugate chemistry[1],[2] is the conjugation of free amines to free thiols. These reactions require heterobifunctional reagents that bridge the two groups. Typical crosslinkers are hydrophobic. Our dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths.

With conventional hydrophobic crosslinking reagents, aggregation and precipitation of the conjugates occur frequently. These problems do not happen with our water-soluble, non-immunogenic dPEG® crosslinkers.

Please contact us at for specific academic pricing.