Fmoc-PEG5-NHS ester contains an Fmoc-protected amine and an NHS ester. The PEG spacer increases the aqueous solubility of the resulting compound. The Fmoc group can be deprotected under basic condition to obtain the free amine which can be used for further conjugations. The NHS ester can be used to conjugate with primary and secondary amine bearing molecules.
Axispharm offers 3000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.