Methyltetrazine-PEG24-amine is an aqueous souluble PEG linker containing a free amine and a methyltetrazine group. Methyl group improves the stability and hydrophilic PEG spacer increases water-solubility. Methyltetrazine enable fast click reaction with TCO (trans-cycloctene), the amine (NH2) group is reactive with carboxylic acid containing molecule in the presence of reagnet such as EDC or HATU. Reagent grade, for research use only.