Cy5-TCO

A TCO-activated Cy5 probe can be used for detection and visualisation 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 cyclo-addition 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 bio-orthogonal reaction pair described to date.