Axispharm provides you with high purity NHS Azidobutyrate which contains one azide and one NHS ester end group. Azides can undergo copper-catalyzed click chemistry reactions with alkynes, DBCO, and BCN. NHS esters can react with amine groups to form stable amide bonds.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.