Methyltetrazine-amido-Tri-(acid-PEG1-ethoxymethyl)-methane is a click chemistry PEG reagent which contains three carboxylic acid groups and a methyltetrazine group. This reagent can react with TCO-containing compounds to form a stable covalent bond without the catalysis of Cu or elevated temperatures. The inverse-electron demand Diels-Alder cycloaddition reaction of TCO with tetrazines is the fastest bioorthogonal reaction with exceptional selectivity. The terminal carboxylic acid can react with primary amine groups in the presence of activators (e.g. EDC, or HATU) to form a stable amide bond. Reagent grade, for research purpose. Please contact us for GMP-grade inquiries.