Product Description: Sulfo-Cy3-PEG2-TCO disodium is a derivative of Cy3 (Cyanine3) (HY-D0822) dye containing sulfonate and TCO groups. The TCO groups of Sulfo-Cy3-PEG2-TCO disodium react with tetrazine functional groups in highly specific click chemistry to form covalent bonds. Thus, Sulfo-Cy3-PEG2-TCO disodium can be covalently bound to some biomolecules (especially antibodies, proteins, etc.) to track their location and dynamic changes in biological samples.