6-TET BCN

6-TET BCN is a clickable derivative of 6-Carboxy-2',4,7',7-tetrachlorofluorescein (6-TET), a widely used green fluorescent dye for biomolecule labeling, particularly oligonucleotides. Spectrally, 6-TET is similar to VIC, JOE, and R6G, and is frequently employed in molecular biology and biotechnology for sensitive labeling and detection applications. The incorporation of a PEG spacer in 6-TET BCN helps reduce steric hindrance and minimizes potential interference with target binding sites, thereby enhancing conjugation efficiency and preserving the functionality of the conjugate. The bicyclononyne (BCN) moiety enables strain-promoted azide-alkyne cycloaddition (SPAAC) with azido groups, forming stable triazole linkages under catalyst-free conditions. In addition, unlike dibenzocyclooctyne (DBCO), BCN also reacts efficiently with tetrazines through an inverse electron-demand Diels-Alder (IEDDA) reaction. This reaction is rapid, selective, and bioorthogonal, allowing labeling of biomolecules under physiological conditions without the need for metal catalysts or disruption of native biological processes.