TCO-PEG12-acid is a aqueous soluble PEG linker attached with TCO moiety. The terminal carboxylic acid can react with primary amine groups in the presence of EDC. This reagent can react with tetrazine-containing molecule to form a stable covalent bond . The inverse-electron demand Diels-Alder cycloaddition reaction of TCO with tetrazines is the fastest bioorthogonal reaction with exceptional selectivity. Reagent grade, for research purpose. Please contact us for GMP-grade inquiries.