Methyltetrazine-PEG*-Azide is a heterobifunctional reagent that
enables simple and efficient post-synthetic incorporation of
tetrazine groups onto alkyne-modified peptides or oligonucleotides.
The click reaction can be performed in organic solvents or aqueous
media. The hydrophilic polyethylene glycol (PEG) spacer arm
enhances solubility in organic solvents as well as in aqueous media
and provides a long and flexible connection.