Cy5-TCO

A TCO-activated Cy5 probe can be used for detection and visualization of tetrazine-containing molecules. TCO moiety reacts with tetrazines to produce a stable, covalent linkage, also referred to as the inverse-electron demand Diels-Alder cycloaddition reaction. This reaction is extremely fast (k > 800 M -1 s-1), selective, and biocompatible. Such excellent reaction rate constants are unparalleled by any other bioorthogonal reaction pair described to date.