Norbornenes, a class of cyclic dienophiles, offer an excellent balance between facile strain-promoted reactivity with tetrazines and overall chemical stability. Tetrazine reacts rapidly with norbornene in aqueous buffer. mPEG modification increases the aqueous solubility of the resulting compound.
Axispharm offers 3000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.