Sulfo-Cy5 NHS ester is a sulfonated, hydrophilic and highly water soluble dye. For the labeling of various amine-containing molecules in aqueous phase, no organic co-solvent is needed. This regent is especially useful for the labeling of proteins which denaturate in the presence of organic co-solvents, as well as for proteins with low solubility. Sulfo-Cy5 NHS ester is one of the most popular fluorophores. In life science, the sulfonate groups make the Cy dyes soluble in water and also reduce fluorescence-quenching which can arise from dye-dye interactions.
Sulfo-Cy5 NHS ester, was conjugated to LLP2A with 646/662 peak excitation/emission in dimethyl sulfoxide. LLP2A exhibited punctate staining around the cell periphery, consistent with it labeling VLA-4 [1].
Reference:
[1] Soodgupta, D. ; Zhou, H.; Beaino, W.; Lu, L.; Rettig, M.; Snee, M.; Skeath, J.; DiPersio, J.F.; Akers, W.J.; Laforest, R.; Anderson, C.J.; Tomasson, M.H.; Shokeen, M. Ex Vivo and In Vivo Evaluation of Overexpressed VLA-4 in Multiple Myeloma Using LLP2A Imaging Agents. Journal of Nuclear Medicine, 2016, 57(4), 640–645.