Methyltetrazine-PEG4-Acid is a stable tetrazines molecule containing a terminal carboxylic acid (CO2H) The terminal acid can react with primary amine groups in the presence of of activators (e.g. EDC, or HATU) to form a stable amide bond. Methyltetrazine enable fast click chemistry with TCO ((trans-cycloctene), methyl group enhances the stability of tetrazine moiety.
