Bioorthogonal Turn‐On Probes for Imaging Small Molecules inside Living Cells

Glowing tags: a series of activatable ("turn-on") tetrazine-conjugated fluorescent probes was developed, which react rapidly in an inverse-electron-demand [4+2] cycloaddition with strained dienophiles such as trans-cyclooctene, thereby strongly increasing the fluorescence intensity. The novel turn-on probes were applied for intracellular live-cell imaging of a microtubuli-binding trans-cyclooctene modified taxol.