Azido-PEG4-(CH2)3-methyl ester is a crosslinker containing an azide group and a methyl ester. The azide group undergoes Click Chemistry with alkynes. The PEG spacer increases the aqueous solubility of the resulting compound. The methyl ester can be easily converted to carboxylic acid and subsequently conjugate to amine containing biomolecules through a stable amide bond.
Axispharm offers 3000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.