Sulfo-Cyanine3.5 is a cyanine fluorophore with fluorescence in the orange spectrum range. Its absorption and emission spectra are between those of Cyanine3 and Cyanine5.
This dye is a sulfonated form of Cyanine3.5 (contains four sulfo groups), so it has good solubility and can be used in reactions without adding organic solvents.
This reagent is a derivative with a free carboxyl group. Because of its inactivity in physiological conditions, sulfo-Cyanine3.5 carboxylic acid derivative can be used as a negative control in experiments with active dye derivatives. The carboxylic acid can be activated with carbodiimides (e. g. EDAC) and react with hydrazines, hydroxylamines, and amines.