Tetra-sulfo-Cy7 DBCO is a bright and photostable near-infrared probe. As a water-soluble hydrophilic dye, Cy7 DBCO is the preferred reagent for applications requiring minimal nonspecific binding and exceptionally high brightness. Its fluorescence remains stable across a pH range of 4 to 10 and exhibits minimal autofluorescence within biological samples in this spectral range. Although the fluorescence of this long-wavelength cyanine dye is not visible to the naked eye, most imaging systems can easily detect it.