The NHS ester can be used to conjugate with amine-bearing biomolecules such as lysine residue on the proteins and amine modified oligonucleotide and biopolymers. After deBoc, the free amine group can conjugate with carboxylic acid bearing biomolecules through an amide coupling process.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.