Cy7.5 alkyne chloride is a derivative of Cyanine 7.5 (Cy7.5) dye that includes sulfonate ions (sulfonate) and an alkyne functional group (alkyne). As a near-infrared fluorescent dye, Cy7.5 is frequently utilized for biolabeling and cellular imaging. Its alkyne group can covalently bond with molecules containing azide groups. Cy7.5 alkyne chloride can bind to biomolecules such as proteins and antibodies, enabling the tracking of their localization and dynamic behavior within biological samples.