Cy7.5 tetrazine tetrafluoroborate is a derivative of the Cyanine 7.5 (Cy7.5) dye that contains a tetrazine group. As a near-infrared fluorescent dye, Cy7.5 is commonly utilized for biomarking and cell imaging purposes. Cy7.5 tetrazine tetrafluoroborate can efficiently undergo click reactions with molecules containing alkyne functional groups, forming covalent bonds. This enables binding with biomolecules such as proteins and antibodies, facilitating the tracking of their location and dynamic changes within biological samples.