Axispharm provides you with high-purity N1,N4-Bisazidospermine bistosylate CAS:2250433-79-3, a spermine linker, which contains an azide group at both ends. The azide group can react with alkynes, BCN, and DBCO to form stable triazole bonds.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.