5-ROX tetrazine
ROX tetrazine is a derivative of ROX (Rhodamine X, Rhodamine 101) dye, a red-emitting fluorophore possessing high brightness and fluorescence quantum yield. This compound contains tetrazine moiety that reacts with trans-cycloalkenes and other strained olefins in inverse electron demand Diels-Alder reaction (IEDDA). The reaction is very quick and specific.