Sulfo-Cy7.5 dimethyl is a derivative of the Cyanine 7.5 (Cy7.5) dye featuring dimethyl groups. The sulfonate ions enhance the compound's water solubility, making it suitable for aqueous solutions. As a near-infrared fluorescent dye, Cy7.5 is commonly employed in biomarking and cell imaging. Sulfo-Cy7.5 dimethyl binds to biomolecules such as proteins and antibodies to track their location and dynamic changes within biological samples.